816 MERCER - Seattle.gov

816 MERCEREarly Design Guidance

project # 3036395-EG816 Mercer Street

714 W. Mercer StreetSeattle, WA 98109

10.21.2020

800 MERCER LLC |

3816 MERCER / EDG / #3036395-EG / 10.21.2020 / /

PROJECT INFORMATION public outreach

SITE

ZONING

CONTEXT

DESIGN APPROACH concept summary approach 1: Seams approach 2: Outdoor Rooms approach 3 (Preferred): Slow Cut landscape

DESIGN GUIDELINES

DEPARTURES

APPENDIX

CONTENTS4-11

12-15

16-19

20-35

36-117

60-9394-117

118-111

130-139

140-143

01

02

03

04

05

06

07

08

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PROJECT INFORMATION

01

5816 MERCER / EDG / #3036395-EG / 10.21.2020 / /

Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan,METI, Esri China (Hong Kong), swisstopo, © OpenStreetMap contributors, and the GIS User Community

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816 MERCER WITHIN SOUTH LAKE UNION

PROJECT INFORMATION

DEVELOPMENT SITE


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SOUTH LAKER UNION

BELLTOWN

QUEEN ANNE

SITE

WESTLAKE

Two new commercial buildings will be located at 816 Mercer and 714 W. Mercer St. ( referred to as the 816 Mercer Project for clarity), between Dexter and 9th. Ave. These buildings will also include a new Seattle Parks and Recreation center for the South Lake Union Neighborhood, as well as a vibrant public realm along the 8th Ave public access easement.

The project goal is to create net positive health; through engaging public space, energy innovation, and informed building massing while creating a stitch between Lake Union and the city at large.

The proposed development consists of:- Two 13-story structures of approximately 414,000 sf and 350,000 sf respectively, above ground- One 30,000 sf recreation center, inclusive of a sport court, within the west building- One tenant meeting space and retail spaces within the east building-Enhanced public realm along the 8th Ave public access easement-Three and a half levels of parking with approximate-ly 600 stalls below grade-Seven loading dock spaces below grade and ac-cessed via 9th Ave.

PROPOSAL / 01

MERCER ST

ROY ST

DE

XTE

R A

VE

9TH

AV

E

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PROJECT INFORMATION

PUBLIC OUTREACH / 03

Early Community Outreach was conducted in accordance with updated requirements from the Seattle Department of Neighborhoods. The team utilized 3 methods for outreach, with comments and methods summarized below.

Methods: Printed Outreach -DIRECT MAILING, HIGH IMPACT -Posters were mailed to 140 residences and businesses and shared with 3 neighborhood community groups. -Date completed: May 20, 2020Electronic/ Digital Outreach -PROJECT WEBSITE, HIGH IMPACT -Project website established and publicized via poster. Monitored daily for comments from the Website. Developed an interactive project website with project information and a public commenting function. -Date Completed: May 20, 2020Electronic/ Digital Outreach -SURVEY, HIGH IMPACT -Online survey established and publicized via poster with link to survey featured on project website -Date Completed: May 20, 2020

Design Related Comments: One respondent noted that utilizing an interesting and unique design would be the most important aspect for a new building on this property. One respondent noted that creating something different and authentic for SLU would be a top consideration in making this building successful.

One respondent noted that landscaping is the most important consideration for the pedestrian only open space design.

Implementation: The design team’s proposed massing seek to not only enhance the character of South Lake Union but create a different approach by looking back at the history and character of place. The 8th Ave public access easement in the proposed design is expanded and enhanced with a focus on landscaping.

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PROJECT INFORMATION

NET POSITIVE HEALTH / 01 AWARENESS OF SELF

Healthier Minds & Bodies

Move, meet, help, retreat

AWARENESS OF CONTEXT

Healthier AppreciationDiverse spaces that stitch together the

neighborhood

AWARENESS OF LEGACY

Healthier Understanding

Dream, Learn, Design, Make, Teach

AWARENESS OF OTHERS

Healthier Communities

A place for all to grow from those around

them AWARENESS OF INNOVATION

Healthier IdeasDirect connection to and inspiration from

breakthrough & impact

AWARENESS OF NEED

Healthier ResourcesEnergy, food, and

resiliency

“...everything leaves the site

healthier than it came...”

The health and viability of the built environment is crucial to the successful longevity of any urban setting. This importance goes beyond just bricks and mortar; it carries through to the residents and occupants who make a place both what it is and what it will become.

Our intent for 816 Mercer is to create an experience that continually delivers Net Positive Health: the opportunity for inhabitants, community, and visitors to leave the site healthier than they came. This aspiration will bolster South Lake Union’s ambition to sustain vibrancy, leverage diversity, and enable equal accessibility to shared resources. We see this as a condi-tion that doesn’t just use the city, but improves it.

Everything leaves the site healthier than it came, today and tomorrow.

THE IMPORTANCE OF AWARENESSIn achieving Net Positive Health, our mandate is to ensure that the importance of urban exposure does not diminish over time through lost visibility and impact. The 816 Mercer project has therefore been framed around “MODES OF AWARENESS” to ensure that attributes key to physical, social, and urban health are sustainable.

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PROJECT INFORMATION

AWARENESS REALIZEDAwareness is the ability for individuals to better understand what improves – or can improve - their lives. It also provides those individuals with critical exposures to the world around them, enabling them to better appreciate what makes life for their local community better too. Net Positive Health at 816 Mercer is realized through six lenses of awareness. In addition to providing greater awareness of SELF and OTHERS around them, the 816 Mercer project is intent on creating introductions to PLACE, NEED, LEGACY, and INNOVATION. Together these aware-nesses are how the project heightens the under-standing of what makes a great urban environment, and specifically in South Lake Union.

AWARENESS / 01

NEEDUrban Agriculture

District EnergyWater Filtering

Thermal Harvesting

OTHERSRec Center

Transparent GroundAccessible Landscape

CONTEXTDistinct Identity

Water AccessPop-up programs

LEGACYEducational Walks

Creative ReferencesStirring Data-points

Materiality

SELFAccess to Nature

Physical MovementIntrovert/Extrovert

Cleaner AirViews

INNOVATIONOpenness of/to floors

Exposed CoresCluster Connectivity

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NET POSITIVE HEALTH IN SOUTH LAKE UNION / 01

Present______________________________________________________ Past___________________________________________________________________

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_Future

streetsMercer, Roy, Dexter, and 9th all have distinct characters. How do we provide tailored, con-

textual solutions?

placeOnce part of Lake Union, originally old Broad Street, how does the develop-ment reference the site’s legacy?

gatewaySLU is changing. The site includes a des-

ignated a gateway corner; how do the key nodes drive towards a sustainable future?

PROJECT INFORMATION

Intentionally applying the construct of net positive health to the 816 Mercer project through the lens of what makes South Lake Union unique will ensure meaningful alignment. The six awarenesses provide a general framework for achieving Net Positive Health, but further analysis of South Lake Union required particular focus. The South Lake Union Neighborhood Design Guide-lines provide strong cues as to how a site can enhance the holistic health of this exciting neighborhood, and form the foundation of our analysis, specifical-ly around streets, gateway, and place.

- The South Lake Union Urban Design Framework outlines the import-ant role Streets play in the experience of this neighborhood; our property is surrounded by four unique street types that can lend to a rich diversity at the perimeter to create a personal connection for all.- As identified in the Framework, this property, specifically the corner of Mercer and Dexter, will play an important role as a Gateway to the area. The outcome may be both a marker and invitation that signify an introduction to the arts and sciences of Seattle Center as well as the innovation of SLU.- SLU’s atmosphere has long been focused on walk-ability and con-nectivity of open spaces. The 816 Mercer site offers the potential for past, current, and future Context to drive a meaningful outcome.

Each of these influences play a distinct role in contributing to both how people enjoy the site and how they will leave feeling better than they came.

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 11

PROJECT INFORMATION

streetsMercer, Roy, Dexter, and 9th all have dis-tinct modes of movement which can lead to tailored experiences at the site edges.

gateway SLU is a major threshold between down-town and Lake Union as well as between Seattle Center and major investments in life sciences and technology. The 816 Mercer project is central to this important intersection

placeBefore the car dictated city planning, connections between Lake Union and Elliott Bay were geared towards pedes-trians and cyclists. The shift of 8th Avenue to a pedestrian-only easement presents an opportunity to restore SLU to multiple modes of movement.

MERCER

9th

ROY

DEXTER

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02

SITE

13816 MERCER / EDG / #3036395-EG / 10.21.2020 / /

SITE

The 816 Mercer site presents a unique opportunity within the South Lake Union neighborhood. It sits on an edge between SLU, Lower Queen Anne, and Seattle Center. It connects a historical waterfront and an international technological and biomedical research hub. It bridges between the highly traf-ficked Mercer Street and the pedestrian oriented Roy Street. It contains the 8th Ave. public access easement, a place that can become a hub of neigh-borhood activity and learning.

Each of these opportunities creates the potential for a place of net positive health through the built environment.

PHOTOS / 02

816 Mercer Site

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SURVEY / 02

SITE

SETBACKS:CURRENT SETBACK REQUIREMENTS SUBJECT TO SITE PLAN REVIEW. CURRENTSETBACKS MAY DIFFER FROM THOSE IN EFFECT DURING DESIGN/CONSTRUCTION OFEXISTING IMPROVEMENTS.THE ISSUANCE OF A CERTIFICATE OF OCCUPANCY BY THE GOVERNING JURISDICTIONINDICATES THAT STRUCTURES ON THIS PROPERTY COMPLIED WITH MINIMUM SETBACKAND HEIGHT REQUIREMENTS FOLLOWING CONSTRUCTION.FLOOD ZONE:THIS SITE APPEARS ON NATIONAL FLOOD INSURANCE RATE MAP, DATED MAY 16, 1995COMMUNITY PANEL NO.53033C0390F, AND IS SITUATED IN ZONE “X”, AREA DETERMINEDTO BE OUTSIDE THE 500-YEAR FLOODPLAIN.

HORIZONTAL DATUM:NAD 2011 EPOCH 2010.00

BASIS OF BEARINGS: N1°28’30”E (CENTERLINE OF DEXTER AVENUE NORTH BETWEEN ROYSTREET AND MERCER STREET.

VERTICAL DATUM:NAVD 88

AREA:SITE AS SHOWN CONTAINS 102,340 SQUARE FEET OR 2.3494 ACRES, MORE OR LESS.

PARKING SPACE COUNT:PARKING SPACES TOTAL 0 INCLUDING 0 DISABLED PARKING SPACES.

SUBSTRUCTURES:BURIED UTILITIES ARE SHOWN AS INDICATED ON RECORDS MAPS FURNISHED BY OTHERSAND VERIFIED WHERE POSSIBLE BY FEATURES LOCATED IN THE FIELD. WE ASSUME NOLIABILITY FOR THE ACCURACY OF THOSE RECORDS. FOR THE FINAL LOCATION OFEXISTING UTILITIES IN AREAS CRITICAL TO DESIGN CONTACT THE UTILITY OWNER/AGENCY.

TELECOMMUNICATIONS/FIBER OPTIC DISCLAIMER:RECORDS OF UNDERGROUND TELECOMMUNICATIONS AND/OR FIBER OPTIC LINES ARENOT ALWAYS AVAILABLE TO THE PUBLIC. BRH HAS NOT CONTACTED EACH OF THEMANY COMPANIES, IN THE COURSE OF THIS SURVEY, WHICH COULD HAVEUNDERGROUND LINES WITHIN ADJACENT RIGHTS-OF-WAY. THEREFORE, BRH DOES NOTACCEPT RESPONSIBILITY FOR THE EXISTENCE OF UNDERGROUNDTELECOMMUNICATIONS/FIBER OPTIC LINES WHICH ARE NOT MADE PUBLIC RECORD WITHTHE LOCAL JURISDICTION. AS ALWAYS, CALL 1-800-424-5555 BEFORECONSTRUCTION.

UTILITY PROVIDERS:

SANITARY SEWER AND STORM DRAINAGE:SEATTLE PUBLIC UTILITIESPROJECT MANAGEMENT AND ENGINEERING700 5TH AVENUEPO BOX 34018SEATTLE, WA 98124-4018(206) 233-7900

WATER:SEATTLE PUBLIC UTILITIES700 5TH AVENUE, SUITE 4900PO BOX 34018SEATTLE, WA 98124-4018(206) 684-3000

POWER:SEATTLE CITY LIGHT700 5TH AVENUE, SUITE 3200SEATTLE, WA 98124-4023(206) 684-3000

NATURAL GAS:PUGET SOUND ENERGY10885 NE 4TH STREET, SUITE 1200PO BOX 97034BELLEVUE, WA 98009-9734(425) 454-6363(888) 225-5773

TELEPHONE:CENTURY LINK1600 7TH AVENUESEATTLE, WA 98191(800) 244-1111

DESCRIPTION:

PARCEL A:

THE WEST HALF OF LOT 6 AND ALL OF LOTS 7 AND 8, BLOCK 1, EDEN ADDITION TOTHE CITY OF SEATTLE, ACCORDING TO THE PLAT THEREOF AS RECORDED IN VOLUME 1OF PLATS, PAGE 61A, IN KING COUNTY, WASHINGTON;

EXCEPT PORTIONS OF SAID LOT 6, BLOCK 1, ACQUIRED FOR STREET PURPOSES BYTHE CITY OF SEATTLE AS PROVIDED BY ORDINANCENUMBERS 84452 AND 88109;

ALSO, THAT PORTION OF LOTS 1 AND 2 IN SAID BLOCK 1, DESCRIBED AS FOLLOWS:

BEGINNING AT THE SOUTHWEST CORNER OF SAID LOT 1;THENCE NORTH ALONG THE WEST LINE OF SAID LOTS 1 AND 2 A DISTANCE OF 120FEET TO THE NORTHWEST CORNER OF SAID LOT 2;THENCE EAST ALONG THE NORTH LINE OF SAID LOT 2 A DISTANCE OF 33 FEET;THENCE SOUTH PARALLEL WITH SAID WEST LINE 107.10 FEET;THENCE SOUTHWESTERLY ALONG A STRAIGHT LINE 35.43 FEET TO THE POINT OFBEGINNING;

ALSO, THAT PORTION OF LOTS 1, 2 AND 8, BLOCK 2 OF SAID ADDITION AND OFVACATED 8TH AVENUE NORTH VACATED PURSUANT TO CITY OF SEATTLE ORDINANCE NO,89653 DESCRIBED AS FOLLOWS:

BEGINNING AT THE SOUTHEAST CORNER OF SAID LOT 1;THENCE WESTERLY ALONG THE SOUTH LINE OF SAID LOTS 1 AND 8 A DISTANCE OF139.48 FEET TO THE SOUTHEASTERLY LINE OF BROADSTREET AS CONDEMNED BY THE CITY OF SEATTLE PURSUANT TO ORDINANCE NO.84452;THENCE NORTHEASTERLY ALONG SAID SOUTHEASTERLY LINE TO THE EAST LINE OF SAID8TH AVENUE NORTH;THENCE SOUTHERLY ALONG SAID EAST LINE 132.87 FEET TO THE PRODUCTION EAST OFTHE SOUTH LINE OF SAID LOT 1;THENCE WESTERLY ALONG SAID PRODUCED LINE 66 FEET TO THE POINT OF BEGINNING;

EXCEPT THOSE PORTIONS OF 8TH AVENUE NORTH, AS VACATED PER CITY OF SEATTLEVACATION ORDINANCE NO. 89653, LOTS 1, 2, 7 AND8, BLOCK 1 AND LOTS 1 AND 9, BLOCK 2, EDEN ADDITION TO THE CITY OF SEATTLEIN VOLUME 1 OF PLATS, PAGE 61A, IN KING COUNTY,PURSUANT TO CITY OF SEATTLE ORDINANCE NO. 125597, MORE PARTICULARLYDESCRIBED AS FOLLOWS:

COMMENCING AT THE MONUMENTED INTERSECTION OF DEXTER AVE NORTH AND MERCERST;THENCE SOUTH 88°41’57” EAST ALONG THE CENTERLINE OF MERCER ST, A DISTANCEOF 112.75 FEET;THENCE DEPARTING SAID CENTERLINE AT A RIGHT ANGLE NORTH 01°18’03” EAST ADISTANCE OF 37.84 FEET TO THE NORTH MARGIN OFMERCER ST AND THE TRUE POINT OF BEGINNING;THENCE NORTH 35°16’26” EAST, A DISTANCE OF 12.32 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE NORTH, WITHA RADIUS OF 1,737.00 FEET, WHICH CENTER BEARS NORTH 06°35’40” WEST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 04°29’51”,A DISTANCE OF 136.35 FEET;THENCE NORTH 78°54’28” EAST, A DISTANCE OF 2.01 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE NORTH, WITH ARADIUS OF 487.00 FEET, WHICH CENTER BEARS NORTH 11°05’32” WEST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 03°19’02”,A DISTANCE OF 28.19 FEET;THENCE NORTH 75°35’27” EAST, A DISTANCE OF 40.73 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE SOUTH, WITHA RADIUS OF 613.13 FEET, WHICH CENTER BEARS SOUTH 14°35’45” EAST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 18°04’38”,A DISTANCE OF 193.45 FEET;THENCE SOUTH 86°31’03” EAST A DISTANCE OF 70.21 FEET;THENCE SOUTH 88°14’25” EAST, A DISTANCE OF 7.51 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE NORTHWEST,WITH A RADIUS OF 65.00 FEET, WHICH CENTER BEARS NORTH 82°57’54” WEST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 59°09’44”,A DISTANCE OF 67.12 FEET TO THE BEGINNING OF ACOMPOUND CURVE, CONCAVE TO THE NORTHWEST, WITH A RADIUS OF 200.00 FEET,WHICH CENTER BEARS NORTH 23°48’10” WEST;THENCE ALONG SAID COMPOUND CURVE THROUGH A CENTRAL ANGLE OF 18°12’00”, ADISTANCE OF 63.53 FEET;THENCE SOUTH 70°01’44” WEST, A DISTANCE OF 10.89 FEET TO THE NORTH MARGINOF MERCER ST;THENCE NORTH 88°33’01” WEST ALONG SAID NORTH MARGIN, A DISTANCE OF 370.46FEET TO THE TRUE POINT OF BEGINNING.

PARCEL B:

THOSE PORTIONS OF BROAD STREET AND 9TH AVENUE NORTH, VACATED PURSUANT TOCITY OF SEATTLE ORDINANCE NUMBER 120863 RECORDED UNDER RECORDING NUMBER20020813000330, AND DESCRIBED IN DEED RECORDED UNDER RECORDING NUMBER20031114001298 (BEING PORTIONS OF LOTS 1, 2, 3 AND 6, BLOCK 1, AND LOTS 1,

2 AND 8, BLOCK 2, EDEN ADDITION TO THE CITY OF SEATTLE, ACCORDING TO THEPLAT THEREOF, RECORDED IN VOLUME 1 OF PLATS, PAGE 61A, RECORDS OF KINGCOUNTY, WASHINGTON, AND PORTIONS OF LOTS 1 AND 2, BLOCK 79, LAKE UNIONSHORELANDS, FILED IN THE OFFICE OF THE COMMISSIONER OF PUBLIC LANDS ATOLYMPIA, WASHINGTON, JULY 1, 1907), ACQUIRED FOR STREET PURPOSES PURSUANTTO CITY OF SEATTLE ORDINANCE NUMBERS 84452,88109 AND 88784, AND PORTIONSOF 8TH AVENUE NORTH AS PLATTED IN SAID EDEN ADDITION, LYING NORTH OF THENORTH MARGIN OF MERCER STREET AND LYING BETWEEN THE FOLLOWING DESCRIBEDLINES “A” AND “B”:

LINE “A”:

BEGINNING AT A POINT ON THE SOUTH LINE OF LOT 8, BLOCK 2, SAID EDEN ADDITION,WHICH LIES 11.48 FEET WEST OF THE SOUTHEAST CORNER THEREOF (SAID SOUTH LINEBEING ALSO THE NORTH MARGIN OF MERCER STREET);THENCE NORTHEASTERLY TO A POINT IN THE EAST LINE OF SAID LOT 8 WHICH LIES 7FEET NORTH OF SAID SOUTHEAST CORNER;THENCE NORTHEASTERLY TO A POINT ON THE EAST LINE OF LOT 2, BLOCK 2, WHICHLIES 85 FEET NORTH OF THE SOUTHEAST CORNER OF LOT 1,SAID BLOCK 2 (SAID EAST LINE BEING ALSO THE WEST MARGIN OF THAT PORTION OF8TH AVENUE NORTH VACATED BY CITY OF SEATTLE ORDINANCE NUMBER 89653);THENCE NORTHEASTERLY TO A POINT ON THE WEST LINE OF LOT 6, BLOCK 1, SAIDPOINT, WHICH LIES 132.87 FEET NORTH OF THE SOUTHWEST CORNER OF LOT 8, SAIDBLOCK 1, (SAID WEST LINE BEING ALSO THE EAST MARGIN OF SAID VACATED 8THAVENUE NORTH);THENCE NORTHEASTERLY A DISTANCE OF 29.20 FEET TO A POINT ON A LINE PARALLELWITH AND 98.17 FEET SOUTH FROM, AS MEASUREDPERPENDICULAR TO, THE NORTH LINE OF SAID BLOCK 1 (BEING ALSO THE SOUTHMARGIN OF ROY STREET);THENCE EASTERLY ALONG SAID PARALLEL LINE TO A POINT ON A LINE WHICH LIES 32FEET WEST OF THE EAST LINE OF THE WEST HALF OF SAID LOT 6, AS MEASUREDPERPENDICULAR THERETO;THENCE SOUTHERLY ALONG SAID LAST-DESCRIBED LINE (32 FEET WEST OF ANDPARALLEL WITH THE EAST LINE OF THE WEST HALF OF LOT 6)21.83 FEET TO THE SOUTH LINE OF LOT 6;THENCE EASTERLY ALONG THE SOUTH LINE OF LOTS 6 AND 3, SAID BLOCK 1, TO APOINT WHICH LIES 33 FEET EAST OF THE WEST LINE OFLOTS 1, 2 AND 3, SAID BLOCK 1; THENCE SOUTHERLY ALONG A LINE, PARALLEL WITHAND 33 FEET FROM, AS MEASURED PERPENDICULAR TO, SAID WEST LOT LINES ADISTANCEOF 107.10 FEET;THENCE SOUTHWESTERLY TO THE SOUTHWEST CORNER OF SAID LOT 1, BLOCK 1 (LYINGALSO ON THE NORTH MARGIN OF MERCER STREET) ANDTHE TERMINUS OF LINE “A”.

LINE “B”:

BEGINNING AT A POINT ON THE SOUTH LINE OF LOT 8, BLOCK 2, SAID EDEN ADDITION,WHICH LIES 79.64 FEET EAST OF THE SOUTHWESTCORNER THEREOF (SAID SOUTHWEST CORNER BEING ALSO THE INTERSECTION OF THEEASTERLY MARGIN OF DEXTER AVENUE NORTH AND THE NORTHERLY MARGIN OF MERCERSTREET);THENCE NORTH 35°15’18” EAST, A DISTANCE OF 38.92 FEET;THENCE NORTH 58°56’02” EAST, A DISTANCE OF 9.05 FEET;THENCE NORTH 29°33’51” WEST, A DISTANCE OF 7.51 FEET TO THE BEGINNING OF ANON-TANGENT CURVE TO THE RIGHT, HAVING A RADIUSOF 1,338.00 FEET, AND HAVING A RADIAL BEARING OF NORTH 27°08’07” WEST TO SAIDBEGINNING OF CURVE;THENCE ALONG SAID CURVE, THROUGH A CENTRAL ANGLE OF 07°05’26”, AN ARCDISTANCE OF 165.58 FEET TO THE BEGINNING OF ANOTHERNON-TANGENT CURVE TO THE RIGHT HAVING A RADIUS OF 956.22 FEET, AND HAVING ARADIAL BEARING OF NORTH 20°36’55” WEST TO SAIDBEGINNING OF CURVE;THENCE ALONG SAID CURVE, THROUGH A CENTRAL ANGLE OF 06°10’27”, AN ARCDISTANCE OF 103.04 FEET TO THE BEGINNING OF ANOTHERNON-TANGENT CURVE TO THE RIGHT HAVING A RADIUS OF 501.24 FEET, AND HAVING ARADIAL BEARING OF NORTH 13°21’39” WEST TO SAIDBEGINNING OF CURVE;THENCE ALONG SAID CURVE THROUGH A CENTRAL ANGLE OF 03°07’36”, AN ARCDISTANCE OF 27.35 FEET;THENCE NORTH 80°52’37” EAST, A DISTANCE OF 15.88 FEET TO THE BEGINNING OF ANON-TANGENT CURVE TO THE RIGHT HAVING A RADIUSOF 379.17 FEET AND HAVING A RADIAL BEARING OF NORTH 08°47’16” WEST TO SAIDBEGINNING OF CURVE;THENCE ALONG SAID CURVE, THROUGH A CENTRAL ANGLE OF 08°39’25”, AN ARCDISTANCE OF 57.29 FEET TO THE BEGINNING OF ANOTHERNON-TANGENT CURVE TO THE RIGHT HAVING A RADIUS OF 140.00 FEET, AND HAVING ARADIAL BEARING OF NORTH 03°46’09” EAST TO SAIDBEGINNING OF CURVE; THENCE ALONG SAID CURVE, THROUGH A CENTRAL ANGLE OF36°51’30”, AN ARC DISTANCE OF 90.06 FEET TO THEBEGINNING OF A TANGENT CURVE TO THE RIGHT HAVING A RADIUS OF 65.00 FEET;THENCE ALONG SAID CURVE, THROUGH A CENTRAL ANGLE OF 115°33’03”, AN ARCDISTANCE OF 131.09 FEET TO THE BEGINNING OF ANOTHERTANGENT CURVE TO THE RIGHT HAVING A RADIUS OF 200.00 FEET;THENCE ALONG SAID CURVE, THROUGH A CENTRAL ANGLE OF 18°12’00”, AN ARCDISTANCE OF 63.53 FEET TO A POINT ON SAID LINE “A” ANDTHE TERMINUS OF LINE “B”;

EXCEPT THOSE PORTIONS OF 8TH AVENUE NORTH, AS VACATED PER CITY OF SEATTLEVACATION ORDINANCE NO. 89653, LOTS 1, 2, 7 AND8, BLOCK 1 AND LOTS 1 AND 9, BLOCK 2, EDEN ADDITION TO THE CITY OF SEATTLEIN VOLUME 1 OF PLATS, PAGE 61A, IN KING COUNTY,PURSUANT TO CITY OF SEATTLE ORDINANCE NO. 125597, MORE PARTICULARLYDESCRIBED AS FOLLOWS:

COMMENCING AT THE MONUMENTED INTERSECTION OF DEXTER AVE NORTH AND MERCERST;THENCE SOUTH 88°41’57” EAST ALONG THE CENTERLINE OF MERCER ST, A DISTANCEOF 112.75 FEET;THENCE DEPARTING SAID CENTERLINE AT A RIGHT ANGLE NORTH 01°18’03” EAST ADISTANCE OF 37.84 FEET TO THE NORTH MARGIN OFMERCER ST AND THE TRUE POINT OF BEGINNING;THENCE NORTH 35°16’26” EAST, A DISTANCE OF 12.32 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE NORTH, WITHA RADIUS OF 1,737.00 FEET, WHICH CENTER BEARS NORTH 06°35’40” WEST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 04°29’51”,A DISTANCE OF 136.35 FEET;THENCE NORTH 78°54’28” EAST, A DISTANCE OF 2.01 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE NORTH, WITH ARADIUS OF 487.00 FEET, WHICH CENTER BEARS NORTH 11°05’32” WEST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 03°19’02”,A DISTANCE OF 28.19 FEET;THENCE NORTH 75°35’27” EAST, A DISTANCE OF 40.73 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE SOUTH, WITHA RADIUS OF 613.13 FEET, WHICH CENTER BEARS SOUTH 14°35’45” EAST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 18°04’38”,A DISTANCE OF 193.45 FEET;THENCE SOUTH 86°31’03” EAST A DISTANCE OF 70.21 FEET;THENCE SOUTH 88°14’25” EAST, A DISTANCE OF 7.51 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE NORTHWEST,WITH A RADIUS OF 65.00 FEET, WHICH CENTER BEARS NORTH 82°57’54” WEST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 59°09’44”,A DISTANCE OF 67.12 FEET TO THE BEGINNING OF ACOMPOUND CURVE, CONCAVE TO THE NORTHWEST, WITH A RADIUS OF 200.00 FEET,WHICH CENTER BEARS NORTH 23°48’10” WEST;THENCE ALONG SAID COMPOUND CURVE THROUGH A CENTRAL ANGLE OF 18°12’00”, ADISTANCE OF 63.53 FEET;THENCE SOUTH 70°01’44” WEST, A DISTANCE OF 10.89 FEET TO THE NORTH MARGINOF MERCER ST;THENCE NORTH 88°33’01” WEST ALONG SAID NORTH MARGIN, A DISTANCE OF 370.46FEET TO THE TRUE POINT OF BEGINNING.

PARCEL C:

LOTS 4, 5 AND 6, BLOCK 2, EDEN ADDITION TO THE CITY OF SEATTLE, ACCORDING TOTHE PLAT THEREOF RECORDED IN VOLUME 1 OF PLATS,PAGE 61A, IN KING COUNTY, WASHINGTON;

EXCEPT THAT PORTION LYING WITHIN DEXTER AVENUE (DEXTER AVENUE NORTH) ANDBROAD STREET, CONDEMNED IN KING COUNTY SUPERIOR COURT CAUSE NUMBER 61981AND 193437 AS PROVIDED BY CITY OF SEATTLE ORDINANCE NUMBERS 17628 AND50890;

AND EXCEPT THAT PORTION LYING WITHIN ROY STREET PURSUANT TO CITY OF SEATTLEORDINANCE NO. 123336.

PARCEL D:

THOSE PORTIONS OF BROAD STREET, 8TH AVENUE NORTH AND MERCER STREET IN THEAREA BOUNDED BY MERCER STREET, DEXTER AVENUENORTH, ROY STREET AND 9TH AVENUE NORTH, AS DESCRIBED IN CITY OF SEATTLEORDINANCE NO. 125599, IN KING COUNTY, WASHINGTON, MORE PARTICULARLYDESCRIBED AS FOLLOWS:

PORTIONS OF BROAD STREET, CONDEMNATION ORDINANCE NOS. 50890 AND 84452, 8THAVENUE NORTH AND MERCER STREET, MORE PARTICULARLY DESCRIBED AS FOLLOWS:

COMMENCING AT THE MONUMENTED INTERSECTION OF ROY ST AND DEXTER AVE NORTH;THENCE SOUTH 01°28’04’’ WEST ALONG THE CENTERLINE OF SAID DEXTER AVE NORTH,A DISTANCE OF 153.09 FEET;THENCE, AT A RIGHT ANGLE, SOUTH 88°31’56” EAST, A DISTANCE OF 53.00 FEET TO APOINT ON THE EAST MARGIN OF SAID DEXTER AVENORTH AND THE TRUE POINT OF BEGINNING;THENCE SOUTH 88°32’51” EAST A DISTANCE OF 13.01 FEET;THENCE NORTH 52°53’29” EAST, A DISTANCE OF 179.96 FEET;THENCE NORTH 88°20’14” EAST, A DISTANCE OF 35.72 FEET TO THE BEGINNING OF ACURVE, CONCAVE TO THE NORTH, WITH A RADIUS OF

35.00 FEET, WHICH CENTER BEARS NORTH 01°41’43” WEST;THENCE ALONG SAID CURVE THROUGH A CENTRAL ANGLE OF 31°52’16” A DISTANCE OF19.47 FEET TO THE SOUTH MARGIN OF SAID ROY ST;THENCE ALONG SAID MARGIN SOUTH 88’32’41’’ EAST, A DISTANCE OF 62.10 FEET;THENCE CONTINUING ALONG SAID SOUTH MARGIN SOUTH 88°33’04” EAST, A DISTANCEOF 67.29 FEET TO THE BEGINNING OF A NON-TANGENT CURVE, CONCAVE TO THENORTH WITH A RADIUS OF 100.00 FEET, WHICH CENTER BEARS NORTH 23°15’55’’ EAST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 19°00’48” ADISTANCE OF 33.18 FEET;THENCE SOUTH 85°44’53’’ EAST, A DISTANCE OF 55.09 FEET;THENCE SOUTH 88°35’57” EAST, A DISTANCE OF 123.52 FEET;THENCE SOUTH 01°43’01’’ WEST, A DISTANCE OF 160.63 FEET:THENCE NORTH 88°48’50’’ WEST, A DISTANCE OF 9.19 FEET TO THE BEGINNING OF ANON-TANGENT CURVE, CONCAVE TO THE WEST WITH ARADIUS OF 65.00 FEET, WHICH CENTER BEARS NORTH 79°15’44” WEST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 60°05’28” ADISTANCE OF 68.17 FEET TO THE BEGINNING OF ACOMPOUND CURVE, CONCAVE TO THE SOUTHWEST, WITH A RADIUS OF 140.00 FEET,WHICH CENTER BEARS SOUTH 40°38’47” WEST;THENCE ALONG SAID COMPOUND CURVE THOUGH A CENTRAL ANGLE OF 36°51’30’” ADISTANCE OF 90.06 FEET TO THE BEGINNING OF ACOMPOUND CURVE, CONCAVE TO THE SOUTH, WITH A RADIUS OF 379.17 FEET, WHICHCENTER BEARS SOUTH 00°06’44” EAST;THENCE ALONG SAID COMPOUND CURVE THOUGH A CENTRAL ANGLE OF 08°39’25” ADISTANCE OF 57.29 FEET;THENCE SOUTH 80°53’45” WEST A DISTANCE OF 15.88 FEET TO THE BEGINNING OF ANON-TANGENT CURVE CONCAVE TO THE SOUTH, WITHA RADIUS OF 501.24 FEET, WHICH CENTER BEARS SOUTH 10°13’°58” EAST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 03°07’36”A DISTANCE OF 27.35 FEET TO THE BEGINNING OF ACOMPOUND CURVE, CONCAVE TO THE SOUTHEAST, WITH A RADIUS OF 956.22 FEET,WHICH CENTER BEARS SOUTH 14°25’20” EAST;THENCE ALONG SAID NON-TANGENT CURVE THROUGH A CENTRAL ANGLE OF 06°10’27’”A DISTANCE OF 103.04 FEET TO THE BEGINNING OF ACOMPOUND CURVE, CONCAVE TO THE SOUTHEAST, WITH A RADIUS OF 1338.00 FEET,WHICH CENTER BEARS SOUTH 20°01’33” EAST;THENCE ALONG SAID COMPOUND CURVE THROUGH A CENTRAL ANGLE OF 07°05’26’” ADISTANCE OF 165.58 FEET;THENCE SOUTH 29°32’43” EAST, A DISTANCE OF 7.51 FEET;THENCE SOUTH 58°57’10” WEST, A DISTANCE OF 9.05 FEET;THENCE SOUTH 35°16’26” WEST, A DISTANCE OF 34.03 FEET;THENCE SOUTH 84°21’54” WEST, A DISTANCE OF 32.96 FEET TO THE NORTH MARGINOF MERCER ST;THENCE CONTINUING SOUTH 84°21’54” WEST, A DISTANCE OF 12.52 FEET’THENCE NORTH 57°22’25” WEST, A DISTANCE OF 2.98 FEET TO SAID NORTH MARGIN;THENCE CONTINUING NORTH 57°22’25” WEST, A DISTANCE OF 17.16 FEET TO THE EASTMARGIN ON DEXTER ST;THENCE NORTH 01°28’04” EAST ALONG SAID EAST MARGIN, A DISTANCE OF 111.22FEET TO THE TRUE POINT OF BEGINNING.

TITLE REPORT REFERENCE:THIS SURVEY WAS CONDUCTED ACCORDING TO THE DESCRIPTION SHOWN, FURNISHED BYCHICAGO TITLE COMPANY OF WASHINGTON, COMMITMENT NO. 190120-SC, SECONDCOMMITMENT DATED APRIL 23, 2019. THE EASEMENTS SHOWN OR NOTED HEREONRELATE TO THIS COMMITMENT.

NOTE: EASEMENTS CREATED OR RESCINDED AFTER THIS DATE ARE NOT SHOWN ORNOTED HEREON.

TITLE REPORT SCHEDULE B EXCEPTIONS:ITEMS CIRCLED ARE SHOWN ON MAP.2. RIGHT TO MAKE NECESSARY SLOPES FOR CUTS OR FILLS UPON PROPERTYHEREIN DESCRIBED, AS PROVIDED BY ORDINANCE NUMBERS. 17628 AND 49108 OFTHE CITY OF SEATTLE.3. RIGHT TO MAKE NECESSARY SLOPES FOR CUTS OR FILLS UPON PROPERTY HEREINDESCRIBED AND THE RIGHT TO DAMAGE THE LANDBY CHANGING AND ESTABLISHING STREET GRADES, AS CONDEMNED IN KINGCOUNTY SUPERIOR COURT CAUSE NO. 193437, AS PROVIDED BY ORDINANCE NO.50890 OF THE CITY OF SEATTLE.5. RIGHT TO MAKE NECESSARY SLOPES FOR CUTS OR FILLS UPON PROPERTY HEREINDESCRIBED AND THE RIGHT TO DAMAGE THE LAND BY CHANGING AND ESTABLISHINGSTREET GRADES, AS CONDEMNED IN KING COUNTY SUPERIOR COURT CAUSE NO.486551, AS PROVIDED BY ORDINANCE NO. 84452 OF THE CITY OF SEATTLE.6. EASEMENT(S) FOR THE PURPOSE(S) SHOWN BELOW AND RIGHTS INCIDENTALTHERETO, AS GRANTED IN A DOCUMENT:RESERVED BY: CITY OF SEATTLEPURPOSE: EXISTING OVERHEAD OR UNDERGROUND UTILITIESORDINANCE NO.:89653AFFECTS: VACATED PORTION OF 8TH AVE NORTH, PARCEL C

7. MATTERS CONTAINED IN THAT CERTAIN DOCUMENTENTITLED: RELEASE OF DAMAGE AGREEMENT, AND THE TERMS ANDCONDITIONS THEREOF:RECORDING DATE: AUGUST 3, 1962RECORDING NO.: 5461596 WHICH PROVIDES FOR AMONG OTHER THINGS:RELEASING CITY OF SEATTLE FROM ALLFUTURE CLAIMS FOR DAMAGES RESULTING FROM PERMISSION TO CONSTRUCT ANDCONNECT SIDE SEWER AND CATCH BASIN REFERENCE IS HEREBY MADE TO SAID DOCUMENT FOR FULL PARTICULARS.SURVEYOR’S NOTE: LOCATION CANNOT BE DETERMINED FROM RECORD DOCUMENT11. MATTERS CONTAINED IN THAT CERTAIN DOCUMENTENTITLED: CITY OF SEATTLE ORDINANCE NO. 120863, AND THE TERMSAND CONDITIONS THEREOF:RECORDING DATE: AUGUST 13, 2002RECORDING NO.: 20020813000330AFFECTS: PORTIONS OF VACATED BROAD STREET, 8TH AVENUE NORTHAND 9TH AVENUE NORTH WHICH PROVIDES FOR AMONG OTHER THINGS: EASEMENT FOR EXISTING OVERHEADOR UNDERGROUND UTILITIES, RIGHT TO MAINTAIN RETAINING WALL, AND RIGHT TOMAKE SLOPES. REFERENCE IS HEREBY MADE TO SAID DOCUMENT FOR FULL PARTICULARS.12. EASEMENT(S) FOR THE PURPOSE(S) SHOWN BELOW AND RIGHTS INCIDENTALTHERETO, AS GRANTED IN A DOCUMENT:GRANTED TO: KING COUNTYPURPOSE:SEWER LINES AND PUBLIC ACCESS FOR PEDESTRIANS ANDBICYCLISTSORDINANCE NO.:125599AFFECTS: VACATED BROAD STREET, 8TH AVENUE NORTH AND MERCERSTREET14. EASEMENT(S) FOR THE PURPOSE(S) SHOWN BELOW AND RIGHTS INCIDENTALTHERETO, AS ESTABLISHED IN CITY OF SEATTLE ORDINANCE NO. 123336:GRANTED TO: CITY OF SEATTLEPURPOSE: 36 MONTH TEMPORARY CONSTRUCTION EASEMENTAFFECTS: PORTION OF LOT 5

15. EASEMENT(S) FOR THE PURPOSE(S) SHOWN BELOW AND RIGHTS INCIDENTALTHERETO, AS GRANTED IN A DOCUMENT:GRANTED TO: KING COUNTYPURPOSE: SEWER PIPELINES, TOGETHER WITH ALL CONNECTIONS,MANHOLES AND APPURTENANCES THERETORECORDING DATE: SEPTEMBER 28, 2018RECORDING NO.: 20180928001996AFFECTS: PORTION OF PARCELS C AND D

JOB NO.: 2019046.04

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 15

SEWER EASEMENTKCRN 20180928001996

SEWER EASEMENTKCRN 20180928001996SEWER EASEMENT

KCRN 20180928001996



WATER PUMP

VENT

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8TH AVENUE NPUBLIC ACCESS EASEMENT

SITE PLAN

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FUTURE 14 STORY OFFICE BUILDING

EXISTING 1 STORYWAREHOUSE

FUTURE 7 STORYOFFICE BUILDING

EXISTING 6 STORYLIFE SCIENCES

BUILDING

EXISTING 1 STORYCOMMERCIAL

BUILDING

EXISTING 6 STORYOFFICE

BUILDING

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EXISTING 6 STORYLIFE SCIENCE

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20’ 1 3/4” 45’ 5 3/4”

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172’ 11 5/8”

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240’ 1 7/8”4’ 2 3/8”

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123’ 6 1/4”88’ 3 1/4”

129’ 4 5/8”55’ 1 1/4”

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SITE PLAN / 02

Information

Address:816 Mercer Street714 W. Mercer StreetSeattle WA 98109

Owner’s Name:

800 Mercer LLC

Architect:

NBBJ

Landscape Architect:

GGN

Site Area: 102,340 SF

Zoning: SM-SLU 175/85-280

Max. FAR: 8.0

Max Height: 175’ non-residential

Existing Conditions

• Dedicated bike lanes on Dexter,

Roy, and 9th Ave.

• Required extension of the Mercer

Ave bike-lane along the S. edge

• 8th Ave. Public Access Easement

(8th Ave. Previously Vacated)

• KC CSO Drop Structure at the

N. end of 8th Ave. public access

easement

SITE

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03

ZONING

17816 MERCER / EDG / #3036395-EG / 10.21.2020 / /

SITE ZONING MAP

Code: Seattle Municipal Code, Title 23, Chapter 48, Mixed

Address: 816 Mercer Street714 W. Mercer StreetSeattle, WA 98109

Zone: SM-SLU 175/85-280

Overlay: South Lake Union Center

Site Area: 102,340 sf

Street Designation: Class 2 Pedestrian Street: Mercer St., Dexter Ave.No Designation: Roy St, 9th Ave N,

ZONING / 03

ZONING

MERCER ST

ROY ST

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10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /18

ZONING

ZONING SUMMARY / 03

23.48.225 – Structure Height: Flight PathE. A proposal to build a structure greater than 85 feet in height in the SM-SLU 85/65-160 and SM-SLU 175/85-280 zones and located north of Mercer Street and West of Fairview Avenue within the South Lake Union Urban Center, requires the applicant to show that the proposed structure height will not physically obstruct use of the flight path shown on Map A for 23.48.225 or endanger aircraft operations.

23.48.225 – Structure Height: A.1 175’

23.48.245 – Upper Level Development: Podium HeightMap A 65’ & 85’

23.48.245 – Upper Level Development: Podium Standards4.b. Podium floor area limits. ... for all the sto-ries below the podium height specified on Map A for 23.48.245, shall not exceed 75 percent of the lot area...

23.48.245. – Open Space RequirementsF.5.C A minimum of 15 percent of the lot area is provided as landscaped open space at ground level, allowing for some area to be provided above grade to adapt to topographic conditions, provid-ed that such open space is accessible to people with disabilities.

23.48.025 – Structure HeightC.7.b No rooftop features are located clos-er than 10 feet to the roof edge.

23.48.245 – Upper Level Development Standards:B.1.d ... is limited to a maximum gross floor area of 24,000 square feet per story,

23.48.240 – Street Level Development StandardsB.2.b Permitted setbacks from street lot lines. Except on Class 1 Pedestrian Streets, as shown on Map A for 23.48.240, and as specified in subsection 23.48.240.B.1, the street-facing facade of a structure may be set back up to 12 feet from the street lot line subject to the following

23.48.245 – Upper Level Development Standards:D.1.d Facade Modulation: 85’-145’ Max Length= 150’ 145+ Max Length= 120’

175’

85’

65’

75% lot area

120’

150’

15’

24,000 sf max

10’

12’

23.48.245 – Upper Level Development Standards:F.5.b A minimum separation of 60 feet is provided between all portions of structures

60’

Mercer St.

9th Ave.

Dexter Ave.

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 19

ZONING

roy

st.85’

+175’

65’

SDOT Sidewalk Right of Way2’ setback up to 8’ in height for ROW

23.48.245 - Podium Height85’ max podium height with 75% coverate

mer

cer s

t.

23.48.065 - Noise & Oder Standards

23.48.075 - Light & Glare Standards

23.48.080 - Required Parking & Loading

23.48.280 - Required ParkingB.1. Maximum allowable parking is 1 per 1,000 sf of gross floor area

23.48.025.C.7 - Rooftop FeatureNo rooftop features are located closer than 10’ from the roof edge

23.48.055 - Landscaping & Screening StandardsA.2. Landscaping that achieves a Green Factor score of .30 or greaterC.3. Parking structure will be below grade

lake union

podium height limit 65’



SMC 23.48.245B.1.d - Gross AreaZone: SM-SLU 175/85-280

Gross floor area above max podium height cannot exceed 24,000 square feet

SMC 23.48.245- Podium HeightAll the stories below the podium height specified on Map A for 23.48.245, shall not exceed 75 percent of the lot area

SMC 23.48.231 - Flight Path

Modification of development standards in certain SM-SLU zonesA.1.b. The non-residential floor plate limits ac-cording to subsection 23.48.245.B.1.d shall be increased from 24,000 to 25,000 square feet

SMC 23.48.025 - Structural HeightZone: SM-SLU 175/85-280

Applicable height limit is 175’ non-residential

Proposed structure height shall not physically obstruct use of the flight path shown on Map A of 23.48.225 or endanger aircraft operations.

23.48.245 – Upper Level Development StandardsZone: SM-SLU 175/85-280

B.4.b For all the stories below the podium height specified on Map A for 23.48.245, shall not exceed 75 percent of the lot area.

All structures with non-residential uses exceeding 85 feet in height, facade modulation is required for the street-facing portions of a structure located within 15 feet of a street lot line. o Between 85’ & 145’ - 150’ o Above 145’ - 120’ per Table B 23.48.245

F.5 Only one tower with non-residential uses exceeding 85 feet in height is permitted on a blockF.5.a If following conditions are met, more than 1 tower is allowed o Lot size is bigger than 60,000 sf o Minimum separation of 60 ft between towers o Minimum 15% of lot area is landscaped

SMC 23.48.020 - Floor Area Ratio [FAR]Zone: SM-SLU 175/85-280

The following are exempt from FAR calculation:

o Below-grade floor area.o Floor area in portions of a story that extend no more than 4 ft above existing or finished gradeo Allowance of 3.5% for mechanical equipment for structure above 65’.o Mechanical equipment located on roof of a structureo Bicycle commuter shower facilities

SMC 23.48.220 – Floor Area Ratio [FAR] Base FAR – 4.5 Max FAR – 8.0

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04

CONTEXT

21816 MERCER / EDG / #3036395-EG / 10.21.2020 / /

CONTEXT

South Lake Union has always been a hub of craft and in-novation. From the Duwamish, to the Western Mill, railway connectivity, and Bill Boeing, SLU has been a location for creation. Now, with Amazon, Google, Facebook, the Allen Institute, Gates Foundation and the UW Medical Research Facility, the demographic has morphed from in-dustry, to technology and thought leaders. Engaging this unique population and leveraging the existing drivers of innovation, provides the site advantageous opportunities

The physical land at 816 is an equally rich tapestry of change and development. Once physically in Lake Union, this site has undergone massive change and development throughout its history. A series of colliding vectors, over time, have all served to create a very distinct, but jum-bled, character and place.

Originally a major connection from Elliott Bay to Lake Union, the 816 Mercer project looks to re-imagine Broad Street site in a more intentional, healthy way.

CONTEXT / 04

SITE

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /22

STREETS / 04

SLU Streets Hierarchy

SITE

Woonerf through and to north of project site prioritizes pedestrian-scale experience while maintaining larger/faster boulevard movement to south and west of project site

This project site, located at the northwest corner of the South Lake Union neighborhood and adjacent to the Queen Anne and Westlake neighborhoods, is situated at the crux of many modes of transportation. It lies on several major commuter routes for automobiles, pedestrians, cyclists, and public transit riders.

Every street bordering the project site currently has, or will have, a protected bike lane. Dexter Ave. is not only a main biking thoroughfare, but also the site of an arterial bus stop moving north-south. Additionally, the South Lake Union Street Car line is within walking distance. Mercer Street to the south is heavily trafficked and will be a newly improved east-west pedestrian and biking experience. 9th Ave is a popular bike transition for those traveling south on Westlake Ave towards downtown. Additionally, with the 8th Ave public access easement and Roy Street, the project site poses a great opportunity to further activate the ground plane and pedestrian connections.

CONTEXT

SITE

LEGENDtraffic volume (AWDT)bike routespublic transit routes

streetcar stopsbus stopspedestrian densities

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 23

CONTEXT

Sit

e

9th

ave

. n.

dext

er a

ve. n

wes

tlake

ave

. n.

terr

y av

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.

bore

n av

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.

fairv

iew

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. n.

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ve. n i-5

Alle

n In

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60

1 D

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0 0.1 0.20.05 Miles

0 0.1 0.20.05 Miles


0 0.1 0.20.05 Miles

0 0.1 0.20.05 Miles

0 0.1 0.20.05 Miles

0 0.1 0.20.05 Miles

Bus Lines

Main Bus StopsStreetcar Rail

SITE

PUBLIC TRANSIT

SITE

Restaurant

Shopping

Coffee

Park

SITE

ACCESSAMENITIES

Secondary Bike Lanes

Protected Bike Lanes

Future Protected Bike Lanes

MERCER ST

ROY ST

DE

XTE

R A

VE

9TH

AV

E

MERCER ST

ROY ST

DE

XTE

R A

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9TH

AV

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MERCER ST

ROY ST

DE

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10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /24

CONTEXT

GATEWAY / 04

SITE

SLU Urban Framework

Diagonal relation between two gateway intersections and access to nearby regional heart

lakeunion

As defined in the South Lake Union Urban Frame-work, the corner of Mercer St and Dexter Ave. is a Gateway Location. Westlake and Roy to the NW is also a Gateway Location. These Gateways mark the transition from South Lake Union to Lower Queen Anne and vice versa, as key nodes as one transitions into downtown. New development, highlighted in orange, is clus-tering around these Gateway locations, project-ing the future of development for the changing neighborhood.

MERCER ST

9TH AVE

DEXTER AVE

LEGEND

Future Development

Gateway location

Research Facilities

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 25

CONTEXT

Seattle centerlooking south-west

Lake unionlooking north-east

Merc

er ave

.

downtownlooking south-east

the Olympicslooking north-west

Mercer blockspanorama from green street @ 175’ (roof deck)

Mercer blockspanorama above 701 dexter

601Dexter

615Dexter

701Dexter

DexterYards

AllenInstitute

MOHAISeattle

GatesFoundation

Sit

e

UW

Med

icin

e Re

sear

ch F

acili

ty

mer

cer s

t.

repu

blic

an s

t.

harr

ison

st.

thom

as s

t.

john

st.

roy

st.

aloh

a st

.

Dex

ter Y

ards

Am

azon

- A

pollo

lake union

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /26

Elliott Bay(Seattle

waterfront)

Lake Union(industrial past)

live(residential)

work(commercial)

PLACE / 04

CONTEXT

site analysisunderstanding edges and site influences

Historically, Lake Union and a steeper topography extended into the present-day 816 Mercer site. The resulting watershed, Native American travel routes, and a later Broad Street connection moved diagonally across the current site to reach the lake. This was a diagonal movement not just of nature, but of people, goods, and automobiles of all speeds and sizes.

As Seattle and its economy grew, a more direct east-west connection was needed from its neighborhoods east of I-5 to Elliott Bay. The Mercer Corridor Plan was born from this need, creating a better pedestrian and cycle experience east-west, right along the south edge of the site. The demolition of the diagonal cut across the site facilitated this east-west connection but lost the relationship to Lake Union.

Re-introducing the diagonal cut across the project site not only acknowledges the site’s topographic and sociological history, but also re-connects Elliott Bay with Lake Union.

Lake Union

Downtown

Natural Environment

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 27

Terrain Relations

Broad StreetConnections

East-West Improvements

Bay Freeway - 1960s Google Aerial - 1990

Aerial - 1960s Mercer Corridor Plan - 2015 Aerial - 2019

Capitol Hill

First Hill

Denny Hill

Queen Anne

Wes

tlake

Broad

StCapitol Hill

First Hill

Denny Hill

Queen Anne

Historic Topography and Watershed Historic Topography w/ Movement Relation to Lake

Settlement Plan - 1899

Capitol Hill

First Hill

Queen Anne

SR-99 I-5

Mercer/Bayview Expressway

Historic Topography w/ Highway Relations to Lake

CONTEXT

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /28

CONTEXT

PLACE / 04

South Lake Union’s built environment developed with industry. First David Denny’s Western Mill, Boeing’s airplane plant, and the Model T factory, the architecture was defined by infrastructure, with 1-2 warehouses and industrial uses required to support manufacturing. Historic platting shows roughly 60’ x120’ parcels, with an alley condition to the southeast, as opposed to the more square blocks to the north west. Often these were combined and amalgamated to create larger footprints to support the industrial uses of the neighborhood.

During the late 1990’s when the neighborhood began to earnestly re-develop, contemporary 7-12 story office and residential towers adjusted the density. While many of the warehouses were demolished, a number remain, their brick shells intact but re-purposed for more commercial uses. Activity, texture, and the human scale is now heavily concentrated at the street level, allowing the towers to encourage development while maintaining a strong sense of place.

Built Environment

240’

240’

60’

120’

240’

60’

110’ 110’

420’

Historical PlattingSDCI Quarter Section: The confluence of two grids ( with and without an alley) bisected by old Broad St.

Industrial Past1-2 story warehouses and other industrial uses focuses texture and scale to the street level.

Maintained Scale and TextureWith the introduction of 7-12 story office and residential re-development, texture and scale is focused to the lower register, allowing the towers to rise above.

AmalgamationFiner sense of scale and texture of parcels becomes amalgamated to support larger footprints and industrial uses.

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 29

400 Fairviewvolume and soffit conditions create an enhanced sense of arrival, pulling pedestrians into the site and development

435 Westlake2 story brick volume, with new commercial programs, maintains scale and texture of the street while providing activation.

CONTEXT

PLACE / 04

Within the framework of any city’s urbanism, there are always projects that challenge and push grand civic thinking. Projects like the Seattle Central Library challenged the notion of a public place, and how the community could engage with a part of the city. In South Lake Union, the Seattle Commons proposal again aspired to redefine public, communal space in Seattle. At the other end of the spectrum, projects like 435 Westlake and Bravehorse on Terry Ave. provide great precedents for maintaining the street scale of South Lake Union critical to maintaining successful, activated urbanism.

In projects like 2+U and 400 Fairview, a highly successful duality exists. Bold, architectural solutions allow for development in new and creative ways, while supporting the scale and street presence that has made South Lake Union successful.

The scale and transformation of the 816 Mercer site requires both solutions. It’s history as part of Lake Union, development and transformation through arterial infrastructure, and now the 8th Ave Public Access easement require a bold civic strategy to public place. Simultaneously, responding to Roy St and Lower Queen Anne, street edge and scale are essential to creating active, engaging neighborhoods.

Built Environment

BO

LD C

IVIC

THIN

KIN

G

NE

IGH

BO

RH

OO

D

SC

ALE

CONFLUENCE OF VECTORS

Seattle Central LibraryShifted volumes and bold architectural character illuminates a new way of thinking about a traditional civic space.

Amazon SpheresA centerpiece to the public realm, the Spheres re-imagine public access to nature in a delightful, healthy way.

Bravehorse_Terry Ave.2 story commercial volume knits itself into surround-ing 8-12 story commercial development

Seattle CommonsSouth Lake Union’s historical precedent for big ideas thinking, and re-imagining the public realm.

2+Uoffice space is lifted off the street through bold architectural thinking. The void is occupied with smaller scale volumes to re-activate the street and maintain scale.

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CONTEXT

Mercer St

Republican St.

Valley St.

Westlake Ave. N

9th Ave. N8th Ave. NDexter Ave. N

Aurora Ave. N

Roy St.

9 BLOCK / 04

LEGEND

Class I Pedestrian Street

Protected Bike Lanes

Class II Pedestrian Street

Neighborhood Green Street

Potential Development

Existing Development

1.

2.

3.

5.

6.

4.

1. 2.

3. 4.

5.

6.

7.

Gateway Location

Transit Stop

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 31

Republican St.

CONTEXT

ARCHITECTURAL LANGUAGE / 04

1. Bill and Melinda Gates Foundation 3. UW Medicine Research Facility Phase 3 4. UW Medicine Research Facility Phase 2 6.Allen Institute 400 Dexter

Research FacilitiesThe southern edge of the site is defined by medical

research facilities. Inward focused compositions of rectilinear glass and metal volumes.

2. 615 Dexter 3. 701 Dexter 4. 701 Valley St. 5. Dexter Yards

Upcoming DevelopmentThe west and northern edges are defined by upcoming commercial developments with two residen-tial projects to the west. To the north, references to the past warehouses of South Lake Union is the predominant language.

6. 820 Roy St.

The adjacent context to 816 Mercer is characterized by predominately two typologies. Firstly, the research campus facilities of The Gates Foundation, Allen Institute, and UW Medical research facilities define a new life sciences hub in Seattle. Secondly, to the north and west, upcoming commercial development. New office and residential developments will shape an active, mixed use, node in South Lake Union.

1. 601 Dexter

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /32Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan,METI, Esri China (Hong Kong), swisstopo, © OpenStreetMap contributors, and the GIS User Community

0 0.1 0.20.05 Miles

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MERCER ST

DE

XTE

R A

VE

N

8TH

AV

E N

9TH

AV

E N

ROY ST

A

B

C

D

Project Site

B. Dexter Ave N Elevation - East

Project Site

A. Mercer St Elevation - North

CONTEXTCONTEXT

STREET ELEVATIONS / 04

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 33

C. Mercer St Elevation - South

Opposite of Project Site

D. Dexter Ave N Elevation - West


CONTEXT

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0 0.1 0.20.05 Miles

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MERCER ST

DE

XTE

R A

VE

N

8TH

AV

E N

9TH

AV

E N

ROY ST

C

D

A

B

A Roy St Elevation - South

Project Site

B. 9th Ave N Elevation - West

Project Site

CONTEXTCONTEXT

STREET ELEVATIONS / 04

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 35

C. Roy St Elevation - North


D. 9th Ave N Elevation - East


CONTEXT

36 10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /

05

DESIGN APPROACH

37816 MERCER / EDG / #3036395-EG / 10.21.2020 / /

DESIGN APPROACH

IDENTITY / 05Further understanding of the site through context analysis, specifically around the site’s streets, gateway location, and histo-ry of place, provided a diverse and layered environment with which to define 816 Mercer, but context analysis also led us to ask a few questions.

How does the design approach and its program elements provide a ranging sense of character to Mercer? It’s critical to understand South Lake Union’s small scale industrial past, but equally leverage the neighborhood’s changing character to ensure a vibrant, active, and engaging site with bold civic thinking.

How are the towers different? The oppor-tunity of a full block site requires that a holistic vision to the development improve the neighborhood and public realm, but in identifiably different ways.

Lastly, how do the recreation center and 8th Ave. public access easement remain distinct and a part of the urban fabric, as opposed to a perceived block amenity?

streets

gateway

placeidentity

characterHow does the design approach define the block? A place to play or a place to think? A place to move or a place to dwell?

distinctionHow does the design approach integrate the full block into the surrounding context? What makes the towers distinct and different?

accessibilityHow does the design approach enhance the highly public elements of the recreation center and 8th Ave public access easement?

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /38

DESIGN APPROACH

APPROACH SUMMARY / 05

gatewayfuture trajectory

anchoring key corners and projecting a sustainable future.

placestoried history

understanding the importance of time and authenticity to root and ground

streetscurrent context

addressing the varied character of the sites urban edges to ensure respon-sivity

In developing the design approaches, the analysis of streets, gateways, and place were deployed as lenses to create distinct identities for each proposal, as well as each building, integrating all elements but with a clearly defined focus.

Approach 1: Tuned Edge, amplifies the varied streetscapes to integrate itself into South Lake Union, establishing a clear dia-logue between Mercer and Roy

Approach 2: Anchored Corner, marks the key corners of the site, using their pres-ence to define site relationships

Approach 3: Slow Cut, re-establishes prevailing movements patterns through the site, from traditional watersheds to Old Broad Street, grounding the development in both the past and future.

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 39

DESIGN APPROACH

approach 1: tuned edge (code compliant)Tower masses justify to urban Mercer, creating an urban edge in contrast to the neighborhood character of Roy. Ground floor program pieces amplify this relationship

Opportunities:-dialogue in edges between Mercer and Roy-ground floor program pavilions respond to “urban” and “neigh-borhood” character, of 9th/Mercer and Dexter/Roy

Challenges:-full block variation-presence at the Gateway Corner-engagement with 8th Ave. public access easement and recre-ation center identity-sunlight & landscape on building terraces

approach 2: terraced cornerTower masses and ground floor program elements are con-solidated in the gateway corner locations, providing a clear sense of presence to the block.

Opportunities:-massing “gateway” and presence at the Gateway location-ground floor program pavilions enhance corner presence from Gateway & Lake Union-massing relief along the 8th Ave. public access easement through terraces

Challenges:-full block variation-similarity of the current context of SLU-increased density along Roy-engagement with 8th Ave. public access easement and recreation center identity-terraces subtract from activity along 8th Ave public ac-cess easement

approach 3: slow cut(preferred)Tower masses cut diagonally across the block, enforcing the sense of movement from prevailing watersheds and Old Broad Street. The raised podium gives prominence to the recreation center and the Slow Cut. Ground floor program elements are placed along the Slow Cut path in-tensifying the experience and identity of the public realm, while creating a greater sense of full block diversity.

Opportunities:-connection to Old Broad and historic sense of place-increase ground level pedestrian space through lifted massing-pavilions have independent identity to the rest of the development-engagement and activation of 8th Ave public access easement through program + movement-independent recreation center identity-tower presence and invitation from Gateway location & from Lake Union-varied scale and mass along all edges & corners yields distinct buildings-distinct building massing concepts that each support the overall slow cut approach.

Challenges:-creating an active streetscape experience with no “back” of the project

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /40

engagerecreation center sport court attracts neighborhood flows

while the amenity space captures SLU movement

tunetowers justify to mercer to allow podium stepping to Roy.

outdoor terraces on mercer engage the city

envelopebaseline building envelope for the site

Approach 1: Tuned Edge, is defined by the site’s varied street-scape. Tower masses are pushed to Mercer St. to establish an “urban edge”, allowing the podium to step down to the north along Roy. Terraces are tuned along Mercer to further engage tenants with city. At the ground plane, the recre-ation center sport court engages the neighborhood flow from Roy and Dex-ter, while the amenity space creates a draw from SLU at 9th and Mercer.

Working within the existing zoning envelope, Approach 1 is confronted with challenges in achieving the rich-ness of character required for a full block development, namely by creat-ing a visual wall along Mercer. Podium terraces face north and receive quite a bit of shade. Lastly, the recreation center struggles to take on an inde-pendent identity and engage the 8th ave. public access easement

Design Guidelines:CS 2.3.h: Adjacent StreetsDC 2.1.a: Massing, Design, & Scale

DESIGN APPROACH

TUNED EDGE / 05(CODE COMPLIANT)

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 41

outdoor terrace amenities engage the city


terraceoutdoor terraces provide visual relief along Mercer, creating

an outdoor urban experience that defines massing

Mercer St Roy St

recreation center

DESIGN APPROACH

streetsthe massing rises up towards the more urban Mercer, and

steps down towards the more pedestrian Roy

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /42

1_Gateway Corner @ Mercer St. and Dexter Ave.


DESIGN APPROACH

DC 2.1.a Massing, Design, and Scale

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 43

SITE

34

21

3_West Building & 8th Ave public access easement @ Roy St. and 8th Ave.

4_West Building @ Dexter Ave. and Roy St.2_East Building from SLU @ Mercer St. and 9th Ave.

DE

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R AV

E

ROY ST

MERCER ST

9TH

AVE


DESIGN APPROACH

DC 3.1.a Building Open Space Relationship

CS 2.3.h Adjacent Streets

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /44

Amenity

8th AvePublic Access

Easement

Tenant LobbyAmenityRecreation CenterMeeting Space

Total Site Area 102,340 sfFAR 7.0 (Maximum 8.0 allowed under code)

Total Floor Area 712,232

Floors 13Height 175’Departures none

+36.5

+37.5

+47

+48.5

+57

+50

+59

+49property line

Mercer St.

Dexter Ave.

Roy St.

9th Ave.

Mercer St.

Tenant Lobby

+60

Amenity+60

Recreation Center Below

+50

Sport Court+50

Bike Storage

+55

Tenant Lobby

+48

+38Meeting Space

+45

Amenity+45

Bike Storage

Garage Access

Garage Access

Ground Floor

+38

L2-4

Tenant

Tenant

211’

184’ 3”

82’6”

230’

150’ 6”

217’

L7

Tenant

Tenant

124’

108’ 6”

230’

217’

97’112’


DESIGN APPROACH

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 45

L5

Tenant

Tenant

211’147’

82’6”

230’

150’ 6”

217’

RoofTerrace

RoofTerrace

112’

L6

Tenant

Tenant

185’

147’

230’

217’

112’

L8-13

Tenant

Tenant

124’

108’ 6”

230’

217’

97’112’

L Roof

124’

108’ 6”

230’

217’

97’112’


DESIGN APPROACH

MechanicalMechanical

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /46


DESIGN APPROACH


E-W Section

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT LOBBY RECREATIONCENTER

L2 +73

L7

GARAGE

GARAGE

GARAGE

GARAGE LOADING DOCK

AMENITYTENANT LOBBY

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

L7

8th Ave.Public Access

Easement

DexterAve.

9thAve.AVG Grade

54’3”

174’ 9” 13’ TYP

23’L1.5 +60L1 +50

P1 +38’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

AVG Grade43’

13’ TYP

L Roof +229’

L Roof +217

174’

L1 +48L1 +38

+38

+50

+59

Key Plan

L2 +61

L5

BIKE STORAGEL1 +50 Amenity

L5

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 47


DESIGN APPROACH

Key Plan

A

A

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

RECREATIONCENTER

BIKE STORAGE

L2 +73

L7

GARAGE

Roy St.

MercerAve

AVG Grade54’3”

174’ 9” 13’ TYP

23’

L1 +50

P1 +38’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

L Roof +229’

+59

L1 +50

GARAGE

GARAGE

GARAGE

L5

Key Plan

LOADING DOCK

AMENITYTENANT LOBBY

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

L7

Roy St.

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

AVG Grade43’

13’ TYP

L Roof +217

174’

L1 +45 +42

L2 +61

Mercer St. +45

TENANT

TENANT

GARAGE

GARAGE

A-A Section B-B SectionMercer EastMercer West

B

B

MEETING SPACE

L5

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DESIGN APPROACH

5_8th Ave Public Access Easement

SITE

5

DE

XTE

R AV

E

ROY ST

MERCER ST

9TH

AVE


816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 49


DESIGN APPROACH

winter solstice12.21

spring equinox3.21

summer solstice6.21

9 am 12 pm 3 pm

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /50

massbaseline massing pushes up against Mercer

TERRACED CORNER / 05

DESIGN APPROACH

anchorVolumetric shifts further engage key corners, anchored by

key ground floor program elements.

Approach 2: Terraced Corner, push-es the tower masses away from the key corners defined in the South Lake Union Urban Framework, creating an outdoor terrace space at the podium, activating these corners at multiple levels. Ground level program ele-ments of the recreation sport court and amenity space are also located at these corners, anchoring the gateway corners.

A subsequent challenge for the ter-raced corner scheme is achieving the desired design guidelines. Setting back from the Gateway Corner strug-gles to maintain the urban edge. The massing shifts, while scaled, fall short of capitalizing on the public realm along the 8th ave public access ease-ment. Also, the recreation center fails to maintain an independent identity to the rest of the development.

Design GuidelinesCS 2.1.b Gateway LocationsDC 2.3.b Street Wall VariationDC 3.1.a. Building Open Space Relationship

terraceTower mass shifts to provide outdoor terraces at key site

corners

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 51


Mercer St Roy St

recreation center

anchortower & ground floor program elements anchor the gateway corner with activity

DESIGN APPROACH

gatewayThe tower masses form outdoor terraces, focusing inward

to 8th Ave public access easement. The overall massing creates a formal gateway at 8th Ave and establishes the

street edges on Dexter and 9th Avenue.

outdoor roomThe grand room formed by the tower massing provides scale

relief to 8th Ave public access easement and activates the space on multiple levels.

volume shifts create terraces

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /52



DESIGN APPROACH

CS 2.1.b Gateway LocationsDC 2.3.b Street Wall Variation


816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 53

SITE

34

21

3_West Building & 8th Ave public access easement @ Roy St. and 8th Ave.

4_West Building @ Dexter Ave. and Roy St.2_East Building from SLU @ Mercer St. and 9th Ave.

DE

XTE

R AV

E

ROY ST

MERCER ST

9TH

AVE


DESIGN APPROACH

DC 2.3.b Street Wall Variation



10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /54

Amenity


Easement

DESIGN APPROACH


DESIGN APPROACH

Total Site Area 102,340 sfFAR 7.5Total Floor Area 771,593

Floors 13Height 175’Departures #1 Rooftop Features #2 Parking Space Size Proportions #3 Lot Line Setback

+36.5

+37.5

+47

+48.5

+57

+50

+59

+49property line

Mercer St.

Dexter Ave.

Roy St.

9th Ave.

Mercer St.

Tenant Lobby

+50

Amenity+50

Recreation Center

+60

Sport Court+50

Bike Storage

+50

Tenant Lobby

+45

+38

Meeting Space

+45Amenity+48

Bike Storage+45

Garage Access

Garage Access

Ground Floor


+57

+48+38

+45

Bike Storage

+38

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 55

DESIGN APPROACH

L2-6

Tenant

Tenant

193’ 6”


152’ 6”

16’ 6”

185’ 6”

66’

82’6” 136’

8’ 6”

99’ 136’

144’

8’

144’

8’

103’ 132’

L8-13

Tenant

Tenant

169’

103’

33’

169’

33’ 103’

33’

99’ 103’

16’6”

119’6”

16’6”

103’ 99’

33’

119’6”

L7

Tenant

Tenant

193’ 6”

152’ 6”

16’ 6”

185’ 6”

66’

82’6” 136’

8’ 6”

99’ 136’

144’

8’

144’

8’

103’ 132’

L Roof

169’

103’

33’

169’

33’ 103’

33’

99’ 103’

16’6”

119’6”

16’6”

103’ 99’

33’

119’6”

RoofTerrace Roof

Terrace

RoofTerrace

RoofTerrace

Potential Roof Terrace

Potential Roof Terrace

Mechanical

Mechanical

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /56


DESIGN APPROACH

Tenant LobbyAmenityRecreation CenterRetail PavilionMeeting Space

E-W Section

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

SPORT COURT AMENITY

RECREATIONCENTER

L2 +73

L7

GARAGE

GARAGE

GARAGE

GARAGE LOADING DOCK

MEETING SPACEAMENITY

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

L7


Easement

DexterAve.

9thAve.AVG Grade

54’3”

174’ 9” 13’ TYP

23’L1.5 +60

L1 +50

P1 +38’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

AVG Grade43’

13’ TYP

L Roof +229’

L Roof +217

174’

L1 +48L1 +38

+38

+50

+59

Key Plan

RECREATIONCENTER

L2 +61

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 57


DESIGN APPROACH

Key Plan

A

A

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

RECREATIONCENTERTENANT

LOBBY

L2 +73

L7

GARAGE

Roy St.

MercerAve

AVG Grade54’3”

174’ 9” 13’ TYP

23’L1.5 +60

L1 +50

P1 +38’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

L Roof +229’

+59

L1 +50

GARAGE

GARAGE

GARAGE

LOADING DOCK

MEETING SPACE

TENANT LOBBY

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

L7

Roy St.

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

AVG Grade43’

13’ TYP

L Roof +217

174’

L1 +45 +42

L2 +61

Mercer St. +45

BIKESTORAGE

TENANT

TENANT

GARAGE

GARAGE

A-A Section B-B SectionMercer EastMercer West

B

B

AMENITY

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DESIGN APPROACH


SITE

5

DE

XTE

R AV

E

ROY ST

MERCER ST

9TH

AVE


816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 59


DESIGN APPROACH

Shadow Studies


spring equinox3.21

summer solstice6.21

9 am 12 pm 3 pm

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /60

invitationtower pinned at the corner rotates in towards the 8th Ave

public access easement, creating a sense of invitation through the site; the east building along an E-W axis to

maintain solar orientation, the west building along a more N-S axis to address the gateway corner. The west tower

faces are chamfered to create a secondary read of scale, as well as greater sense of invitation.

gatewaybaseline massing anchors the gateway corners while shift-ing to provide a relief in density along both Mercer and Roy

SLOW CUT / 05(PREFERRED)

DESIGN APPROACH

Approach 3: Slow Cut, re-imagines old Broad Street, physically connecting the site to Elliott Bay and Lake Union along existing watersheds, and grounding the proposal in the historicity of place. Two dis-tinct massing concepts support the overall Slow Cut approach. Pinned at the gateway corner the towers angle in towards the 8th Ave public access easement at different angles, defining a sense of invitation while suggesting movement into, as opposed to around, the site. Ground floor program elements are situated along this path, and adjacent to the 8th Ave public access easement, activating the public realm. The podium mass is lifted along the slow cut to clearly distinguish a public “room”, expand-ing the pedestrian area three-dimension-ally. This shift greatly varies the character along the different edges and corners of the site, creating two distinctly different buildings that both support the Slow Cut approach.

Design GuidelinesCS 2.4.b. Full Block SitesCS 2.3.h. Adjacent StreetsCS 2.1.b. Gateway LocationsPL 1.1.b. Street Level Open SpacePL 1.1.c. Open Space ConnectionsDC 2.2.a. Street level ScaleDC 2.1.a. Massing, Design, & ScaleDC 2.4.a. Response to Context

slow cutat Mercer West, the podium shifts vertically along the Slow-

Cut to create varied & scaled urban rooms and a generous public space below. The recreation center sits prominently

along Mercer engaging the 8th Ave public access easement. The ground floor level at Mercer East breaks down in scale

both horizontally and vertically, engaging people through vary-ing levels, entries, and programs, in particular, at the 8th Ave.

public access easement.

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 61

placethe slow cut re-imagines Broad Street as a highly active,

pedestrian environment, engaged with the recreation center, bike parking entry, child care, amenity spaces,

and future developments across Roy

public!shifted podium allows for increased poros-ity into the public realm

Dexter Ave 8th Ave Public Access Easement

recreation center


DESIGN APPROACH

two systems: shell and stacksthe perimeter of Mercer West creates a “shell” that is cut to provide invitation into

the slow cut, building entries, and outdoor terraces. The urban shell responds to the scale of the city while the cuts take on a more tactile, human scale.

Mercer East takes on a volumetric approach; distinct stacks meet the sky through the tower and define streetscapes through the podium. These two elements sit on

a scaled ground level, also cut back, that defines the Slow Cut

corner presence and creating invitation

systems that inform movement

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DESIGN APPROACH

CS 2.3.h Adjacent StreetsThe tower folds back from the

corner of Dexter and Roy to present a smaller scale to the

neighborhood to the northwest

DC 2.1 Massing, Design, and ScaleMercer East is comprised of a distinct ground level, mid-tier, and tower massing each reacting to specific site conditions.

CS 2.4.B Full Block SitesMercer West and Mercer

East have two distinct massing concepts that

both support the Slow Cut approach.

PL 2.2.b Walkways and Pedestrian InterestThe recreation center is a focal feature along Mercer and the 8th Ave public access ease-ment drawing people into the public amenity.

CS 2.1.b Gateway LocationsVertical ‘pin’ at the corner of

Mercer and Dexter responds to the similar vertical move

at 601 Dexter creating a ‘gateway’ corner.


PL 1.1.c Street Level Open SpaceBy lifting the Mercer West podium, the Slow Cut is introduced at the ground level creating a visual link from Seattle Center to Lake Union.

DC 3.1.a Building Open Space RelationshipBy raising the podium level, a public space is created for the recreation center and additional public out-door space. Varying programmatic elements along the 8th Ave public easement creates a vibrant pubic realm.

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 63

SITE

34

21


3_The Hub & 8th Ave public access easement @ Roy St. and 8th Ave.

4_The Hub Arrival @ Dexter Ave. and Roy St.2_The Exchange from SLU @ Mercer St. and 9th Ave.

DESIGN APPROACH

DE

XTE

R AV

E

ROY ST

MERCER ST

9TH

AVE

DC 2.4.a Response to ContextThe two distinct massing concepts that support the larger Slow Cut approach respond to their immediate and larger con-texts in scale, proportion, and massing geometry.

CS 2.D.3 Zone TransitionsMercer West presents a gateway marker at the corner of Dexter and Mercer. From there, the tower peels back in two folds to decrease the mass at the corner of Dexter and Roy in recognition of the smaller, neighborhood scale to the northwest.

CS 2.B.2 Connection to the Street

The street front of Mercer East presents a smaller scale, two-story face. This pedestrian scale horizontal volume

is further broken down horizontally to express entries, changes in program,

and level changes that correspond to the sidewalk grades.

DC 2.3 Building PodiumThe building volume is clearly delineat-

ed by three horizontal zones: base, mid-tier, and tower. The base responds

to the pedestrian realm in scale and relationship to the sidewalk. The mid-tier

responds to adjacent building heights and angles back as an invitation into the Slow Cut. The tower is set back further

from Mercer and Roy to reduce scale.

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Easement

DESIGN APPROACH



DESIGN APPROACH

Total Site Area 102,340 sfFAR 7.5Total Floor Area 771,593

Floors 13Height 175’Departures #1 Rooftop Features #2 Parking Space Size Proportions #3 Lot Line Setback #4 Facade Modulation #5 Podium Height

+36.5

+37.5

+47

+48.5

+57

+50

+59

+49property line

Mercer St.

Dexter Ave.

Roy St.

9th Ave.

Mercer St.

Tenant Lobby

+60

Amenity+57 Recreation

Center +60

Sport Court+50

Bike StorageBelow

+50

Roof Deck+60

Tenant Lobby

+48

Amenity+60

Amenity+48

Amenity+38

Meeting Space

+45

Amenity+45

Garage Access

Garage Access

Ground Floor

L2

TenantRoof

Terrace

Tenant

220’

90’

90’

106’

157’

110’

Meeting Space

+38

BikeAccess

117’

134’

L5-6

Tenant

Tenant

220’

225’

90’

141’

160’

225’

134’235’

195’

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DESIGN APPROACH

L3

Tenant

Tenant

Roof Terrace

220’

90’

90’

141’

160’

225’

134’235’

Roof Terrace

Roof Terrace

L4

Tenant

Tenant

220’

90’

90’

141’

160’

225’

134’235’

L7

Tenant

Tenant

225’

195’

Roof Terrace

Roof Terrace

Roof Terrace

L8-9

Tenant

Tenant

225’

195’

90’

110’

233’

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DESIGN APPROACH


DESIGN APPROACH

L10

Tenant

Tenant

90’

90’

110’

233’

196’

70’

Roof Terrace

L11-13

Tenant

Tenant

90’

90’

110’

233’

196’

70’

L ROOF

90’

90’

110’

233’

196’

70’

PotentialRoof Terrace Mechanical

Mechanical

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DESIGN APPROACH


DESIGN APPROACH

Tenant LobbyAmenityRecreation CenterRetail PavilionMeeting Space

E-W Section

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

SPORT COURT

RECREATIONCENTER

BIKE STORAGE

TENANT LOBBY RECREATIONCENTER

L2 +73

L7

L 10

GARAGE

GARAGE

GARAGE

GARAGE LOADING DOCK

MEETING SPACETENANT LOBBY

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

L7


Easement

DexterAve.

9thAve.AVG Grade

54’3”

174’ 9” 13’ TYP

23’L1.5 +60

L1 +50

P1 +38’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

AVG Grade43’

13’ TYP

L Roof +229’

L Roof +217

174’

L1 +48L1 +38

+38

+50

+59

Key Plan

L2 +61

BIKE STORAGE

55’

10’ 8’

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DESIGN APPROACH

Key Plan

A

A

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

RECREATIONCENTER

BIKE STORAGE

RECREATIONCENTER

L2 +73

L7

L 10

GARAGE

Roy St.

MercerAve

AVG Grade54’3”

174’ 9” 13’ TYP

23’L1.5 +60

L1 +50

P1 +38’ 6”

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

L Roof +229’

+59

GARAGE

GARAGE

GARAGE

LOADING DOCK

MEETING SPACE

TENANT LOBBY

MECHANICAL

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

TENANT

L7

Roy St.

P2 +29’ 6”

P3 +19’ 6”

P4 +10’ 6”

AVG Grade43’

13’ TYP

L Roof +217

174’

L1 +45 +42

L2 +61

Mercer St. +45

AMENITY

TENANT

TENANT

GARAGE

GARAGE

B

B

A-A Section B-B SectionThe ExchangeThe Hub

26’

20’ 26’

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DESIGN APPROACH


SITE

5

DE

XTE

R AV

E

ROY ST

MERCER ST

9TH

AVE


DESIGN APPROACH


DESIGN APPROACH

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DESIGN APPROACH


Shadow Studies


spring equinox3.21

summer solstice6.21

9 am 12 pm 3 pm

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DESIGN APPROACH


The Slow CutUrban to Individual

At the heart of the 816 Mercer site is the 8th Ave public access easement, a highly public, accessible amenity for South Lake Union and the city at large. The Slow Cut approach actively expands this public space at multiple scales, reinforcing it’s im-portance as an urban amenity. As opposed to a “short cut”, the Slow Cut is imagined as a place to pause and dwell.

At the urban scale, the Slow Cut is a phys-ical re-connection of Elliot Bay to Lake Union, with the 8th Ave public access easement at the heart. Referencing Old Broad Street and historical transportation routes, the Slow Cut looks to stitch togeth-er existing patterns of movement within South Lake Union and Seattle.

Approaching the site, both buildings are designed to create a sense of invitation into the 8th Ave public access easement. At the lower levels of both towers, the massing is pulled back along this path, physically inviting pedestrians into, as op-posed to around, the site.

For the individual, the Slow Cut is acti-vated through a series of unique massing moves. Lifting the podium to define a space for the recreation center sport court at Mercer West, cascading terraces at Mercer East, and a vibrant, layered land-scape strategy all work together to create a dynamic pedestrian realm

The Slow CutUrban to Individual

INVITATIONThe two towers employ a number of strategies to

create a sense of invitation, specifically into the 8th Ave public access easement at the heart of the Slow

Cut. Tower orientation, raised podium, ground floor cut backs, and a high degree of transparency constantly reveal 8th Ave to pedestrians approaching from the

Gateway Corner and Lake Union.

CONNECTIONRe-imagining Old Broad Street and historical routes, the Slow Cut, at the urban scale, is a physical connection of

Elliot Bay to Lake Union. The last large development in South Lake Union, the Slow Cut, reconnects this historic

past, stitching together the old and new.

ACTIVATIONAs opposed to a simple path, or “short cut”, the Slow

Cut is imagined as a place to stay and dwell. Ame-nities, landscape features, distinct programs, and

unique massing moves serve to activate the 8th Ave public access easement into a new, highly accessi-

ble public realm for South Lake Union.

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DESIGN APPROACH

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DESIGN APPROACH

1

2

3

4

5

6

7

8

At the heart of the Slow Cut approach is the opportunity to recreate an historical pathway in the urban streetscape. The Slow Cut stitches together lost connec-tions from Elliott Bay to Lake Union at both a civic and pedestrian scale. By raising the podium at Mercer West, framed views are created at the upper levels and, at the same time, space is created below to intro-duce the Slow Cut path from the gateway corner. The terraces, horizontal massing, and ground floor folds into the Slow Cut at Mercer East create a sense of invitation into the site.

ConnectionStitching the City

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2

1

1 View from the Space Needle

The Slow Cut at the city scale:The invitation into the Slow Cut is seen from the Space Needle through to MOHAI and Lake Union. The distinct massing of the buildings reinforces the Slow Cut and acts as a marker in South Lake Union. 2 Aerial from Lake Union

Broad Street legibility:From Lake Union to Seattle Center the Slow Cut reads at the city scale.

DESIGN APPROACH

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DESIGN APPROACH

4

3

3 View from Mercer + Aurora

The Gateway:The corners of 601 Dexter and Mercer West create twin vertical anchors that frame the Gateway. At Mercer West the Gateway folds back and the podium lifts upwards creat-ing both the invitation into the Slow Cut and framed views through the site at the ground and upper levels. 4 View from Roy + Westlake

Invitation:From the corner of 9th Ave. and Roy Street, the ground plane folds back from the street creating the invitation into the Slow Cut. The colonnade frames the Slow Cut pathway and the towers angle into the 8th Ave public access easement.

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6

5

5 View from 8th + Republican

Podium Lift:The 8th Ave public access easement is framed by the podium lift to the west and the shifting volumes to the east. The space beneath the lifted podium is activated by the recreation center and the increased public area. The horizontal volumes enforce the invitation into the public ease-ment and create active terrace spaces overlooking 8th Ave. 6 View from 8th + Valley

Active Space:The framed view of the 8th Ave public access easement is reinforced by the raised podium and the shifted volumes of Mercer East. The space is activated by distinct architectural moves, various program-matic elements, level changes, and multiple building entries.

DESIGN APPROACH

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DESIGN APPROACH

7 Aerial from Across Mercer

Framed Views:The raised podium creates framed views through the Slow Cut at both the pedestrian level and upper floors.Shifts in massing both at the ground plane and tower reinforce the invitation into the 8th Ave. public access easement.

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8 Aerial from Across Roy

Distinct Place:The raised podium, recreation center pavilion, visible structure, and the 8th Ave. public access easement create a unique and distinct destination for South Lake Union and Seattle at large.

DESIGN APPROACH

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amenity

lobby

lobby

meeting

spaceamenity

amenity

amenity recreationcenter

sportcourt

deck

ramp to

bike parking

mercer st

mercer st

roy st

roy st8thave

dexterave

9thave

bike parking

DESIGN APPROACH


Tenant LobbyAmenityRecreation CenterMeeting SpaceBike Storage

Slow CutEntrance

At the heart of the Slow Cut is the 8th Ave public access easement. Within the ground plane, a num-ber of strategies are utilized across the site to not only expand and enhance the physical space of the public realm ( through the podium lift) but create a new type of public space in South Lake Union. Rather than a “shortcut” through the site, the Slow Cut is activated through a number of moments to encourage pedestrians to stay and dwell.

-Building masses cut back substantially along the slow cut, physically increasing the size and expe-rience of the 8th Ave public realm.-The landscape design of 8th Ave provides a sense of public continuity, while enhancing the movement and activation of the Slow Cut.-The recreation center sport court sits prominently along 8th ave + Mercer, clearly denoting the acces-sible public nature of 8th Ave. - A deck in the northeast corner of Mercer West provides a potential outdoor space for the recre-ation center.-A meeting space at the corner of Mercer and 9th provides a draw for the public from South Lake Union.-Active programs around the site meet the substan-tial grade changes, allowing multiple entires with varying heights and scales.-Bike park entries are clear, distinct, and highly vis-ible, but also take you to storage and lockers below grade, allowing for more active uses at grade.- Most back of house functions, including the load-ing dock and waste storage, are pushed below grade, freeing up the ground plane for maximum porosity and accessibility.

ActivationEnhancing the Pedestrian Experience

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DESIGN APPROACH

Views from Roy StreetBy raising the podium space for the recreation center sport court additional public amenity space is created.

Views from Mercer and the 8th Ave Public Access Easement

The sport court, child care, amenity spaces, multi-level terraces and lobby entries all acti-vate the 8th Ave public access easement.

The raised podium creates framed views through the Slow Cut and a bold architectural expression.

The sport court marks the invitation into the Slow Cut from Mercer Street.

The invitation into the Slow Cut is framed by the ground floor massing of Mercer East and the raised podium and sport court at Mercer West

Within the 8th Ave public access easement, framed views towards Lake Union are revealed.

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DESIGN APPROACH

The HubMercer West

The Hub building, or Mercer West, begins with the Gateway Corner of Mercer and Dexter. To-gether with the 601 project across Dexter Ave, this building creates a distinct vertical marker, defining the gateway into SLU. The tower mass-ing this peels back to provide relief off of Mercer, respond to the street edge along Dexter, and de-fine the urban scale slow cut. What distinguishes the Hub is a podium lift along Mercer and the 8th ave public access easement. Simply lifting the podium mass to match the UW Campus height across Mercer allows the space of the public access easement to expand in and towards the recreation center. It also provides porosity and site lines into the slow cut, and finally creates a volume within which the recreation center sport court can be placed prominently. This pavilion, distinct from the tower massing and expression, allows the recreation center its own identity along 8th, serving to amplify and enhance the civic character of The Hub.

gatewayBaseline massing responds to the Gateway Corner of Mercer and Dexter. Holding a presence, and anchoring this corner, re-sponds to the neighboring context.

slow cut invitationTower reorients to reduce the scale of the building along Mercer, while beginning to open up to the 8th ave public access ease-ment.

liftPodium massing along Mercer and 8th ave is lifted to define an urban room. This lift is critical to creating a high degree of porosity and transparency into 8th ave.

activationAmplifying the highly public nature of 8th ave, the recreation sport court is place at the corner of 8th and Mercer, activating the slow cut while providing this urban amenity a presence to the city.

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DESIGN APPROACH

gateway pinMassing anchors itself at the Gateway Corner, relating to adjacent context and defining the entry into South Lake Union.

civic presenceThe Hub’s lifted podium is it’s defining feature, intentionally creating an expanded volume along the 8th ave public access easement to physically enlarge the pedestrian realm. Simultaneously, this lift provides a volume for the recreation center sport court, whose presence on Mercer and 8th again defines the civic nature of the Hub.

!

urban shellThe Hub’s architecture is defined by the “urban shell. A

continuous mass tracing around the building that is “cut” to reveal the slow cut, or allow access to nature.

podium liftThe podium massing is lifted off Mercer and 8th ave, expand-ing the public realm and providing an identity to the recreation center sport court

chamferThe tower massing adds a unique chamfer element, reducing the overall impact and scale of the tower, while allowing light to penetrate into both 8th ave. as well as Roy St.

scaled streetsThe “shell” anchors the Gateway Corner, but

elsewhere is lifted, allowing for a more scaled response to each street edge.

from the Exchange terrace along 8th ave

framing viewsFrom the 8th ave public access easement, the podium lift frames view corridors, including the

Space Needle

creating invitationLooking north from across Mercer, the podium lift

and sport court geometry clearly suggest move-ment into the slow cut.

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DESIGN APPROACH

The ExchangeMercer East

The Exchange begins with Roy and Lake Union. Mitigating the scale change from South Lake Union to Westlake, the Exchange is imagined as a series of distinct, stacked components, and in-dividually address contextual drivers and streets. The tower massing at the top also reinforces the slow cut, creating a presence and vista from Lake Union at the corner of 9th and Roy, and peeling back into the 8th ave public access ease-ment. The podium, or middle volume, addresses existing podium datums around the site, while holding the various street edges. Finally, the base, or the lower 40’ springs free from the podi-um geometry above. This allows for scaled ter-races, at the corner of 8th and Mercer to reduce the scale of the building within the pedestrian realm, as well as 9th and Roy, a unique massing move in regards to corners, that also addresses the lower buildings to the site’s north east. Final-ly, the base pulls back along Roy, completing the slow cut, and encouraging movement into the pedestrian realm of 8th ave.

tower & podiumDistinct tower and podium elements sit atop one another. Massing is pushed off Mercer to provide relief to each street.

invitationTower reorients to reduce the scale of the building along Roy, while beginning to open up to the 8th ave public access easement.

slow cut & stackA ground level setback to 8th ave along the slow cut further breaks the building down into a stack of 3 distinct components: tower, podium, and base. Pulling in the base cre-ates a high degree of transparency into 8th ave and the slow cut.

scaled terracesThe podium volume is shifted to create a number of scaled terraces. These terraces match adjacent datums around the site.

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DESIGN APPROACH

shifted stacksThe Exchange is clearly divided into three distinct components: the tower, the podium, and the base. A shift in the podium geometry breaks down the scale of the tower through a series of low level terraces. Pulling back the base at the ground floor completes the slow cut, pulling people from and to Lake Union.

from the Dexter Yards along 8th ave

street continuityThe more “neighborhood” exchange provides a

continuous sidewalk along 8th ave, stitching 816 into the existing streetscape.

neighborhood scalePulling back the massing of the base provides a

plaza just off 8th ave, activating the public realm with a more neighborhood scale.

scaled terracesShifted podium massing creates scaled, responsive terraces on Roy St and 9th Ave, as well as Mercer and the 8th ave public access easement

neighborhood podiumThe Exchange podium expresses

itself as a clear volume, shifted amongst the tower and base. This

element relates to existing podium datums, contextualizing the building

within the neighborhood.

inviting baseThe Exchange base, or lower 40’, is pulled back along Roy to

create invitation into the slow cut.

urban towerThe tower volume reinforces the slow cut through it’s orientation, pulling in from Roy and 9th Ave towards the 8th ave public access easement.

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DESIGN APPROACH

Responding to Context

The 816 site engages four distinct streetscapes, and four distinct neighborhood characters. With no alley or “back door”, ensuring appropriate con-textual responses to these different characters is critical to the development’s success. Always reinforcing the Slow Cut, and enhancing the pedestrian realm of the 8th Ave public access easement, both the Hub and the Exchange ad-dress the different street edges as the buildings respond to speed, scale, and context.

Mercer St: Gateway PresenceAs the largest and fastest edge of the site, Mer-cer St. requires a bold response to hold its urban presence, and yet entertain a variety of modes of engagement.

Dexter Ave: Urban TransitionA main arterial connection to the north, the massing along Dexter is focused on encouraging urban activity and transition.

Roy St: Neighborhood ScaleRoy street is the “slowest” of the edges, and is therefore focused on the experience of pedestri-ans and cyclists.

9th Ave: Lake to CityThe shortest edge on the site, 9th Ave connects the smaller scale developments along Lake Union with the towers of Downtown Seattle.

Mercer St

Valley St.

9th Ave. N8th Ave. NDexter Ave. N

Roy St.

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9th Ave. looking south2

9th Ave. looking north

1

4

Roy. looking east

3

1

4

Dexter Ave. looking south

2

3

Dexter Ave. looking north

1

Mercer St

Valley St.

Mercer St. looking west

5

4

Mercer St. looking east

2

1

UW Medical

3


DESIGN APPROACH

SITE

A

DE

XTE

R AV

E

ROY ST

MERCER ST

9TH

AVE

site plan

A B

B

C

D

C

D

E F

E F

H

G

G

H

summary of street responses

Roy St. looking west

6

5

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Mercer StGateway Presence

As the largest and fastest edge of the site, Mer-cer St. requires a bold response to hold its urban presence, and yet entertain a variety of modes of engagement. 1- The tower anchors the gateway corner of Dexter and Mercer, but unlike the experience on Dexter, the massing ele-vates the podium to mark a strong, but inviting street edge.

2- The lift of the podium gives individual identity for the recreation center, communicating its importance as a highly public amenity as well as a distinct draw into the Slow Cut. The podium is lifted to match the UW Campus across Mercer, rein-forcing the existing context 3- A secondary massing fold creates a clear invitation to the Slow Cut, and the highly visible recreation center. 4- While still holding the Mercer edge, the mid-tier, hori-zontal band reduces the overall scale of the Exchange by creating a series of terraces along Mercer. Cascading from the Hub, and from Seattle Center to the Lake, these terraces at the Exchange provide smaller scaled elements along the Mercer frontage. 5-The ground floor horizontal volume folds to mark the main entrance into the building, as well as define the meeting space at the corner of Mercer and 9th.

DESIGN APPROACH


5

4

1

THE HUB

THE EXCHANGE

2

3

4

5

UW Phase 3

Allen Institute

UW Phase 2

601 Dexter


2

1

UW Medical

3

meeting space

rec center

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DESIGN APPROACH

Dexter AveUrban Transition

A main arterial connection to the north, the massing along Dexter is focused on encouraging urban activity and transition. 1- The tower anchors the gateway corner at Dexter and Mercer, but peels back to introduce a change in scale from Mer-cer to Roy. The reduction in scale along Dexter to Roy addresses the zone transitions from SM-SLU 175/85-280 to SM-UP and LR3RC to the west and northwest respectively. 2- The low podium face holds the street edge to re-inforce and urban corridor with street activity. A landscaped terrace on the roof of the podium creates energy at this mid-level, relating in scale to buildings along Dexter.

3- The ground level steps back at the northwest cor-ner to create an intimate scale, complementing the pedestrian facades along Dexter, while establishing a clear, distinct entry.


1


2

3

12

3

Dexter Yards

UW Phase 3

601 Dexter

615 Dexter

701 Dexter

Dexter Yards

THE HUB

daylight

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6

5


DESIGN APPROACH

Roy StNeighborhood Scale

Roy St is the “slowest” of the edges, and is there-fore focused on the experience of pedestrians and cyclists. 1- At the Exchange, the ground-floor horizontal volume angles back from the corner of 9th and Roy as an invitation to the Slow Cut.

2- The colonnade frames movement into the Slow Cut and, along with the bicycle parking entry, defines the plaza space between the building and Roy Street.

3- Two terraces at different levels create a secondary scale that relates to adjacent buildings and creates multiple points of interaction along Roy Street.

4- Podium lift along the 8th Ave public access easement defines a moment of invitation into the Slow Cut, while creating an urban room for the recreation center.

5- The only vertical element- the northeast corner of the Hub tower- is a tall landmark that identifies a place to stop, and move through the 8th Ave public access easement and Slow Cut.

6- The Hub building folds inwards to create a transition in scale and greater landscape activity along Roy St, both at the ground plane and elevated terrace. At the base this move high-lights the entry and activates the Dexter & Roy corner. The reduc-tion in street front massing along Roy Street addresses the zone transition from SM-SLU 175/85-280 to SM-SLU 85/65-160.

THE HUB

THE EXCHANGE

Allen Institute Dexter Yards

601 Dexter

615 Dexter

701 Dexter

1

2

5

6

3

4

Roy. looking east

3

1

4

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DESIGN APPROACH

9th AveLake to City

The shortest edge on the site, 9th Ave spans between the quieter experience of Roy and the speed & activity of Mercer 1- The three horizontal volumes of the Exchange step back from Mercer to the corner of 9th and Roy marking the intro-duction into the slow cut from the lake. 2- The ground floor volume folds back from Roy Street towards the 8th Ave public access easement as the invitation into the slow cut.

3- With no “back door” to the overall property, the loading access is placed across from the Allen Institute’s back of house ground level facade.

4-The lower podium at the south east corner is grounded by a meeting space that draws people from the north, south, and east of South Lake Union.



1

4

1

2

3

THE EXCHANGE

4

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DESIGN APPROACH

Exercising Scale

Both the Hub and the Exchange utilize scale changes to address the varied context of the 816 Mercer site, as well as enhance and amplify the Slow Cut. XS: At street level, where people most frequently engage the buildings, ground level programs are arranged to provide interest and variation at the finest scale. Referencing South Lake Union’s original 60’ platting increments, entryways, materiality, possible spill out spaces and canopies create a lively streetscape. S: Slightly larger pavilions of the recre-ation center, child care, and meeting space, an-chor the streetscape volumetrically, and provide another layer of richness to the ground plane. M: Moving into the tower, unique massing moves at each building differentiate the two tow-ers. The massing fold at The Hub pulls you into the Slow Cut from the Gateway corner, as well as reducing the overall scale of the tower along Roy. At the Exchange, the shift in horizontal volumes creates scaled terraces on all four street edges. L: The “shell” of the Hub creates a bold civic presence at the Gateway corner of Mer-cer and Dexter. Conversely, the neighborhood Exchange is clearly broken into three elements: tower, podium, and base, for a more scaled re-sponse. XL: Anchored corners at Dexter and Mer-cer and 9th and Roy mark gateway and define the slow cut.

street-scapeThe Hub and the Exchange meet the ground with an intentional focus on the human scale. Street frontages are activated with programs that contribute to the neighbor-hood and are enriched with opportunities to spill outside. Possibilities for articulation, materiality, canopies, and entry definition will further add a sense of tactility and vibran-cy to the street experience.

XSpavilion programsThe recreation center sport court, child care, and the work lounge/ entry into bicycle parking act as “objects in the landscape”. Taking on a character independent of the tow-ers, these programs define and anchor the ground plane, especially along the 8th Ave public access easement. Varying in scale, and potentially changing materiality, the pa-vilions serve to add another layer of legibility to the ground plane. Along Mercer the size and scale of the meeting space similarly creates a connection to South Lake Union.

Sobject identityactivating engagement

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!

!

dexter ave

mercer st

mercer st

roy st

roy st

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DESIGN APPROACH

folds and terracesAt The Hub, tower facades are folded to respond to different conditions around the site: along Mercer St, the fold creates a sense of invitation into the Slow Cut, as well as bringing down the scale of the tower. Along the northern edge, this fold peels back the tower to minimize the presence along Roy, and allow more daylight into the street. At the Exchange, shifts in the horizontal stacking of elements create scaled terraces along all four streets. These terraces provide a legibility to the stacking, and bring down the scale of the building while providing activation and amenity.

Mshell and stacksAt the Hub, the massing responds to the Gateway corner of Mercer and Dexter with a continuous vertical face, connecting this gateway from ground to sky, as well as to the adjacent context. This “shell” then wraps the entire building in a continuous, clear, and civic gesture. The neighborhood scale of the Exchange is more broken down. Tower, po-dium, and base are clearly articulated, breaking down the scale into distinct elements.

Lanchored cornersThe project is defined by the Slow Cut. Starting at the Gateway Corner of Mercer and Dexter, the Hub tower angles into the 8th Ave public access easement, defining the Slow Cut, and creating a much greater sense of invitation into the 8th ave public ac-cess easement. At the Exchange, the tower massing also angles into 8th ave. Together this xl scale orientation of towers enhances the urban move of the slow cut.

XLunique moments of scale creating invitationneighborhood character

anchored corner

anchored corner

carved shell

towerpodiumbase

scaled terraces

scaled folds

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05

LANDSCAPE

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LANDSCAPE / 05

LANDSCAPE

The scale and location of this project offer a number of unique opportuni-ties for the landscape to support the project goal of net positive health. The project site currently sits at the edge between ecologies, urban scales, and communities. As places of meeting and interaction, edges are some of the most productive condi-tions. The 816 Mercer site connects three key conditions: land to water, the global city to a changing neigh-borhood, and a innovative workplace with a community recreation center. Each of these edges presents an opportunity for interaction and dia-logue to enrich the public realm and support a healthier Seattle.

streetscurrent context

addressing the varied character of the sites urban edges to ensure respon-siveness

placestoried history

understanding the importance of time and authenticity to root and ground

gatewayfuture trajectory

anchoring key corners and projecting a sustainable future.

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LANDSCAPE

Early connections focused on a NS orientation linking Lake Union to Downtown and the waterfront by rail.

Proposals for freeways in the mid twentieth century highlight the shift in priority toward moving vehicles be-tween Aurora Avenue and I-5. This focus persists today.

Current planning in the South Lake Union Framework Plan shows a diversity of street types to support the large-scale regional connections like Mercer Street, as well as woonerfs and green streets to enhance the pedestrian neighborhood experience.

The industrialization of early Lake Union had a strong connection to the surround-ing blocks of warehouses. As the lake industries declined and the city grew, connecting freeways became the priority. Numerous plans were drawn for elevated freeways along the southern edge of Lake Union. While opposition to these projects ultimately caused their cancellation, the expansion of Mercer Street is a legacy of this era. The removal of the Broad Street exit allows this mega-block site to open back up to the street grid. North-south connectivity can link the growing neighbor-hood to the north of the property with the rapidly developing territory south of Mer-cer. Increased bicycle and pedestrian con-nectivity is essential in creating a healthier environment for people.

StreetsConnecting the Global City & Emerging Neighborhood

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Healthier Movement

Diverse street characters build on SLU Framework plan and enhance options for pedestrians and bicycles

Mercer Street

8th

Ave

nue

Roy Street

9th

Ave

nue

Dex

ter A

venu

e

Aur

ora

Aven

ue

LANDSCAPE

The project enhances opportunities for pedestrians and cyclists throughout. Surrounding streetscapes and the “Slow Cut” connection through the 8th Avenue public access easement will improve the experience of moving through this part of the city, shifting away from a car-domi-nated character. Building setbacks allow for substantial new planting areas that will improve the psychological experi-ence and environmental quality for all those moving through and around the site.

The design builds on the South Lake Union Framework Plan in multiple ways. At the corner of Mercer Street and Dex-ter Avenue the project celebrates this “high-ground gateway” through building massing and planting at the corner. The

project proposes an Urban Village Neigh-borhood street on Roy Street to anchor the developing neighborhood to the north with a new crossing at 8th Avenue easement to slow vehicles. The exten-sion of the separated bike lane along Mercer Street from Dexter up to 9th will also improve this important city connec-tor. Existing separated bicycle lanes on 9th Avenue and Dexter Avenue will also be maintained giving these blocks a high degree of bicycle connectivity.

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LANDSCAPE

Denny Park to the south brackets the 8th Avenue Green street with a double block.

Lake Union Park sits only a block away to the northeast along Roy Street.

Seattle Center

Queen Anne

South Lake Union

East Lake

Lake Union

Denny Park

Lake Union Park

The site is at the boundary of multiple neighborhoods and identities. While the site has been a barrier in recent decades, it’s future can be one that strength-ens existing community destinations, while simultaneously creating a sense of place, home and community for the neighborhood. By linking the performing arts and the life sciences with a festive 8th ave and an engaged ground plane experience, the site can become the hub for South Lake Union life.

GatewayConnecting Workplace and Community

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Healthier Community

LANDSCAPE

Promoting fitness, community activities, and environmental benefits will support a healthier community. The project Slow Cut encourages interaction with others and the environment. The rec center lo-cated within the project will be a hub for activity.

The site design supports this healthier community by emphasizing connectivity as well as places to gather. Streets maxi-mize opportunities to connect with na-ture and reap the benefits of physical ac-tivity. The public realm is also understood as a place of mixing where daily building tenants will share the ground plane with those using the rec center, child care, and the public outdoor spaces. Such in-

teractions are an essential component of a healthy public realm where all feel safe and welcome.

Rec Center

GatewaySLU

to Lake Union Park

to Lake Denny Park

8th Ave public access easement

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Development incrementally extended boardwalks and filled around the edge of Lake Union

LANDSCAPE

Prior to infilling around the edge of Lake Union, water occupied the northeast-ern corner of this parcel. The lake edge was a dynamic ecosystem closely tied to the topography and soil character of the area. Peat soils extending to the southwest held water in perched bogs. A diversity of plants, insects, and animals were all adapted to these conditions.

The lake edge was also regularly occu-pied by Indigenous peoples who made seasonal camps near the site and ben-efited from this rich interface between land and water. Over years of fill con-nected with the industrial growth of

Lake Union and the surrounding city, this unique ecology was largely erased. To-day’s site sits a block beyond Lake Union but the topography still orients toward the lake edge. Significant increase in impervious surfaces mean that water moves much more quickly over paving, increasing temperatures and picking up contaminants. Tree canopy is largely gone, and the native plants so critical to the insects at the base of the food web are all but absent. The site design high-lights this lake-edge character by accen-tuating the topographic shift across the property through planting and water to bring the ecological health and function back to this edge.

PlaceConnecting Land and Lake

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Healthier Ecology

Planting throughout express transition toward lake and integrates storm water

Examples of native plant species well suited to build up the ecological health of the site and connect to the historic lake-edge character

LANDSCAPE

This project looks to reconnect the lake-edge identity and regenerate the rich ecology disrupted in recent years. The site design highlights this lake-edge character by accentuating the topo-graphic shift across the property and through planting and water to bring the ecological health back to this edge.

Planting will feature native species that support the identity and ecology of the context. Planting design is approached through the lens of ecological perfor-mance as well as appearance. Species mixes will improve soil health over time. Plants are understood as the base of a food web that supports the insects that

are food for birds. Focusing on species that support pollinators and birds will support South Lake Union’s role as a connector between larger natural patch-es within the city. Daily connection with this ecology also has health benefits for all visiting or passing by the site through contact with nature in the city.

Storm water management is also a pri-ority for the project within the site and in the streetscapes. The site proximity to Lake Union and steep slopes make this a critical zone for slowing and filtering every drop of water that lands within the site connecting hydrology to the project goal of net positive health.

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Dex

ter A

ve. N

9th

Ave

. N

8th

Ave

. N

Mercer St.

Roy St.

LANDSCAPE

The HubThe Exchange

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The site design connects the site narrative of land and water with the contemporary network of streets and spaces to support a public realm that will enhance the project’s vision of “net positive health” for all who en-gage the site.

Site Diagram

LANDSCAPE

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extent of 8th Ave public access easementRec Center

Sport Court

LANDSCAPE

Returning the 8th Ave Public Access Easement (PAE) to the public realm will return the mega block to the urban fabric once again. The project approaches this space through the three primary project concepts: Street, Gateway, and Place. The proposed design connects these three approaches to ensure clear public move-ment through the site while also shaping a space for gathering and activity. The design also seeks to further the story of this unique site accentuating the topogra-phy to break down the overall scale of the space and introducing native planting and stormwater throughout.

8th Avenue Public Access Easement

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LANDSCAPE

2. Strategies for Programming and Operations

• Street level uses on 8th Avenue should be designed to attract and retain non-formula programming

• Variety of ground level uses with varied street presence

• Common building entrances independent of street level uses but not mirrored across

• Third party programming opportunities for public space reflecting community interests and temporary events

Summary of SDC Guidelines for 8th Avenue

Design Response

1. Emphasize Pedestrian

• Restricted vehicle access• Festival street designation for frequent programming

and activation• Promote and favor pedestrian connections with

widened sidewalks, expanded landscaping, and materials that blend into adjacent ROW design

• Street furnishing to promote social interaction independent of building function

• Public art should be integrated and not an extension of the private development

• Equity in the design of public space should be embraced

3. Embrace Nature• Public legibility through connection to adjacent

streets• Cohesive design adjacent streetscape species • Promote high-functioning landscapes and explore

integration of natural drainage features

1. StreetOne of a series of green-street blocks, 8th Ave extents the basic street framework and materiality to extend the public realm through the site.

2. GatewaySupporting Rec Center program and a gathering space that is connected to adjacent buildings and supports activation

3. Place8th Avenue connections Mercer Ave to Roy St and the historic lake edge. Accentuating topography, water, and planting across the site

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The basic framework for the landscape is that of the street. The design for 8th Avenue directly connects to the SDC guidelines for the space—in particular, the street framework plan for blocks south of Mercer Street. The basic components of a clear path of travel along building edges, two rows of trees, and widened zones of paving and furnishing will mean that the proj-ect is clearly visible as an extension of the street vocab-ulary from adjacent blocks.

1. StreetPublic Pedestrian Connection

8th Avenue Guidelines (South of Mercer)SDC Guidelines for 8th Avenue PAE highlight connecting to the framework for blocks to the south of Mercer Street.

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Proposed DesignBuilding on the typical street and guidelines for 8th Avenue, the project maintains the clear structure of paths of travel and trees while expanding the amenity zone given this is not a vehicular drive.

Typical StreetTypical framework of a public street

Clear Path of Travel

Clear Path of Travel Mercer Street

Roy Street

8th

Ave

nue




Amenity Zone

Amenity Zone

AmenityZone

Amenity Zone

Roadway

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8th Avenue sidewalk looking north

Looking north from 8th Avenue south of project

Cross view toward Rec Center

8th Avenue central space looking toward Roy Street

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2’ x 2’ concrete paving

native planting

seat steps

King County utility

stormwater planting

wooden bench

tiered seating element

stage/plinth

plank paving

movable furnishing

Mercer Street

Roy Street

8th

Ave

nue

Materials

Furnishing

Planting

2’ x 2’ city standard concrete sidewalk

integrated seat steps and plinths fixed wooden benches

Drier and sunnier planting seasonally wet planting and bioretention

movable furnishing

open-jointed plank paving

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8th Avenue PAE is a place to connect a diverse popula-tion. The central space is comprised of a series of pub-lic rooms that can work independently or collectively for maximum programming flexibility. When no event is taking place the design breaks down the overall scale to pedestrian connections for a welcoming experience activated by the daily life of the neighborhood. The central room has a direct relationship to the Rec Cen-ter to enhance its civic character and central gathering potential.

2. GatewaySpaces for Public Life

Potential public activities balance daily life with collective events

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Example test fits of possible programming games + seating small event for 120 festival tents

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The public street framework overlays with the diago-nal of the Slow Cut through multiple points of interest and paths of travel. As the Slow Cut also relates to the site’s topography, this becomes an opportunity to celebrate the landform and break down the overall project scale with numerous moments of prospect and refuge.

The story of water is central to the history of this lake edge site and the contemporary sustainability of the place. The revised design for 8th Avenue establishes the central street space as a mixture of paved “plat-forms” over a continuous soil volume that will gather and convey water falling onto 8th Avenue. This design integrates public gathering spaces with the sustain-able infrastructure for the site and connects project concepts with ecological performance.

3. PlaceEmbracing Site and Sustainability

Example native species for seasonally wet and shadier portions of the site

Example native species for drier and sunnier portions of the site

Symphoricarpos albus

Camas

Rosa gymnocarpa

Polystichum munitum

Lupinus latifolius

Iris tenax

Deschampsia cespitosa

Tellima grandiflora

Plectritis congesta

Gaultheria shallon

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bioretention within planting areas

platform soil cell zone

continuous soil cell

collectproject

Mercer Street

Roy Street

8th

Ave

nue

Topography can invite play Example of combining social space and stormwater

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1

1

4

4

5

6

5

Existing condition at King County Utility. Grade constraints necessitate that the low wall be maintained.

2

2

3

3

The elevation and location of the various elements of the King County utility do not allow for a direct acces-sible connection of the western sidewalk alignment as it continues north across Roy Street. Given the im-portance of this basic urban structure to connect the space to the framework of adjacent blocks, the revised design acknowledges and incorporates this constraint by extending the clear path of travel sidewalk further north to the utility and has added two accessible routes around the fixed utility elements to maximize porosity and connectivity. Because screening of these elements would add to their disruption of the critical path of travel, the project has identified a series of potential opportunities to integrate art or site elements that can celebrate this moment of transition and leverage the disruption.

King County UtilityIntegrating and celebrating infrastructure

+49.0

+49.5

+49.7

+48.4

+49.0

+49.0

+46.8

extent of below-grade utility

existing retaining wall

existing access path

6

7

7

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potential art/ gateway element

potential secondary path

potential art/ gateway element integrated with required site wall

primary sidewalk alignment

primary accessible pathway

View looking south from 8th Avenue and Roy Street emphasizes greater continuity of the street. Circulation and art/interpretation opportunities around the utility.

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Section A - Roy Street

Section B - Roy Street

LANDSCAPE

The HubThe Exchange

E

A B

D

C

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Section C - Mercer Street Section D - 9th Avenue

Section E - Dexter Avenue

LANDSCAPE

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DESIGN GUIDELINES

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CS 2 Urban Pattern & Form

A. Location in the City and Neighborhood1. Sense of Place2. Architectural Presence**CS2.1.b Gateway Locations

B. Adjacent Sites, Streets, and Open Spaces1. Site Characteristics2. Connection to the Street**CS2.3.h Adjacent Streets3. Character of Open Space

C. Relationship to the Block3. Full Block Sites**CS2.4.b Full Block Sites**CS2.4.c Mid-Block Connections

D. Height, Bulk, and Scale3. Zone Transitions4. Massing Choices

CS 1 Natural Systems & Site Features

A. Energy UseC. Topography**CS1.3 Topography and Elevation Changes

CS 3 Architectural Context and Char

A. Emphasizing Positive Neighborhood Attributes4. Evolving Neighborhoods

B. Local History and Culture1. Placemaking

PL 1 Connectivity

A. Network of Open Spaces1. Enhancing Open Space2. Adding to Public Life**PL1.1.a Mid-Block Connections**PL1.1.b Street Level Open Space**PL1.1.c Open Space Connections**PL1.1.d 8th Ave North

B. Walkways and Connections3. Pedestrian Amenities**PL2.2.b Walkways and Pedestrian Interest

PL 4 Active Transportation

B. Planning Ahead for Bicyclists1. Early Planning2. Bike Facilities3. Bike Connections

DC 2 Architectural Concept

A. Massing1. Site Characteristics and Uses2. Reducing Perceived Mass**DC2.1.a Massing, Design, and Scale**DC2.2.a Street-level Scale**DC2.3.b Street Wall Variation**DC2.4.a Response to Context

DC 3 Open Space Concept

A. Building-Open Space Relationship1. Interior / Exterior Fit**DC3.1.a Building Open Space Relationship

B. Open Space Uses and Activities3. Connections to Other Open Space

C. Design1. Reinforce Existing Open Space

CS 1 Natural Systems & Site Features PL 1 Connectivity

CS 2 Urban Patter & Form

CS 3 Architectural Context & Character




** Asterisk represents South Lake Union Design Guideline additions; all other guidelines from the Seattle Design Guidelines

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A. Energy Use

1. Energy Choices: At the earliest phase of project development, examine how energy choices may influence building form, siting, and orientation, and factor in the findings when making siting and design decisions.

ARCHITECT’S RESPONSE:

816 Mercer plans to take part in a district energy development utilizing heat from the existing sewer system infrastructure. Where possible, components of the district energy system will be highlighted and displayed for public viewing and education.

Management of site drainage has the opportunity to be an integral component in achieving the project’s sustainability goals and site planning. The proposed drainage design focuses on expressing storm water on the surface while achieving necessary treatment and mitigation. The drainage system will consist of bio-retention facilities, conveyance channels and runnels, a detention facility, and a piped overflow conveyance system.

C. Topography

2. Elevation Changes: Use the existing site topography when locating structures and open spaces on the site. Consider “stepping up or down” hillsides to accommodate significant changes in elevation. **CS1.3 - Topography and Elevation: Accommodate sloping terrain through “stepping” ground floor and other architectural features. Emphasis should be placed on ground-level treatments that create a safe, attractive transition between the site and pedestrian zone.


From the corner of Dexter and Mercer at the Southwest to the corner of 9th Ave N and Roy Street at the Northeast, there is approximately 22’ of grade change.

On the ground floor and through landscape terracing, the design mitigates the grade change through a series of changing levels - within the building and in the landscaping. These grade changes are made more apparent in the preferred approach where the ground plane in each building is marked by a massing transition that allows more porosity and diverse open spaces that mitigate the elevation changes. Each of the main entries will have a generous and level transition from the exterior ground plane to the interior and will be set back as required to make that transition. A variety of entries into the buildings at different grades allow access to the different program elements and allow pedestrian movement through the buildings. These access points act as smaller scale Slow Cuts through the buildings that work in conjunction with the larger Slow Cut through the 8th Ave public access easement. (see page 64 for ground floor entries and elevations)

CS 1 Natural Systems & Site FeaturesDESIGN GUIDELINES

Dexter +59

9th Ave N +37

+50

8th Ave N public access

easement

+48

Roy St

Mercer St

Dex

ter A

ve N

9th

Ave

N

+59

+37

The HubThe Exchange

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CS 2 Urban Pattern & FormDESIGN GUIDELINES

A. Location in the City and Neighborhood

1. Sense of Place: Emphasize attributes that give Seattle, the neighborhood, and/or the site its distinctive sense of place. Design the building and open spaces to enhance areas where a strong identity already exists, and create a sense of place where the physical context is less established. Examples of neighborhood and/or site features that contributed to a sense of place include patterns of streets or blocks, slopes, sites with prominent visibility, relationships to bodies of water or significant trees, natural areas, open spaces, iconic buildings or transportation junctions, and land seen as a gateway to the community.


The project site is located at a unique location - at the intersection of Lake Union, Seattle Center, and Denny Park - each located in different neighborhoods with their individual architectural identities. Additionally, the project site is close to a north-south thoroughfare (Aurora Ave N) and an east-west thoroughfare (Mercer St). As such, the preferred massing aims to establish a distinctive sense of place primarily through the “Slow Cut” - angling the massing back to allow diagonal pedestrian connection across the project site at the ground plane and visual connection through views framed by the towers. Lifting the podium at Mercer West emphasizes the neighborhood connection by creating the physical and visual connection from the Space Needle to Lake Union while providing a central community heart at the center of the project. (see pages 72-81 for more information)

2. Architectural Presence: Evaluate the degree of visibility or architectural presence that is appropriate or desired given the context, and design accordingly. A site may lend itself to a “high-profile” design with significant presence and individual identity, or may be better suited to a simpler but quality design that contributes to the block as a whole Buildings that contribute to a strong street edge, especially at the first three floors, are particularly important to the creation of a quality public realm that invites social interaction and economic activity. Encourage all building facades to incorporate design detail, articulation, and quality materials.**CS2.1.b - Gateway Locations: The South Lake Union Urban Design Framework (UDF) identifies important gateways to consider in project design. Gateways are transition locations and places that mark entry or departure points to the neighborhood for automobiles and pedestrians. Private sites at gateways should create opportunities for identification - a physical marker so the community notices they are entering a special place. ARCHITECT’S RESPONSE:

The Mercer/Dexter corner of the project site sits at an identified Gateway. Additionally, near the northeast approach to the site, are two other Gateways and a “Heart.” These SLU DG distinctions, along with Lake Union, Seattle Center, and Denny Park and their historical connections, are the impetus behind the “Slow Cut” preferred approach.

The “Hub” in the preferred massing shares one corner of the Dexter / Mercer Gateway marker. To respond, the corner of Mercer and Dexter is vertically continuous, which ‘pins’ this point with a vertical anchor and mirrors a similar ‘pin’ at 601 Dexter. The massing then peels off of this vertical anchor to further emphasize the gateway and lower the street edge scale along Dexter for a better pedestrian experience. The peeling motion is applied at multiple scales in response to the Slow Cut concept as well as other adjacent building contexts.

Lifting the podium at the Hub highlights both the public recreation center and the invitation into the Slow Cut in a single grand gesture emphasizing the importance of this new public space and its acknowledgment of the historical diagonal connection from Seattle Center to Elliott Bay.

Altogether, the “Hub”’s architectural presence at the Mercer/Dexter corner gives the project a unique form within the context of South Lake Union and creates a building-scale marker within the community. Together with the “Exchange,” the preferred scheme builds an exciting precedent in its creation of a quality public realm that invites social interaction and economic activity. (See pages 72-91 for more information)

MERCER ST

9TH AVE N

DEXTER AVE

ROY ST

WESTLAKE AVE

HEAVY N-S ROADWAY

AURORA AVE

LAKE UNION

SEATTLE CENTER

DENNY PARK

8TH AVE N

VE

RTI

CA

L PI

N

VE

RTI

CA

L PI

N

GATEWAY

INVITATION INTO SLOW CUT

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12

3

Dexter Yards

UW Phase 3

601 Dexter

615 Dexter

701 Dexter

Dexter Yards

THE HUB

daylight

DESIGN GUIDELINES

B. Adjacent Sites, Streets, and Open Spaces

1. Site Characteristics: Allow characteristics of sites to inform the design, especially where the street grid and topography create unusually shaped lots that can add distinction to the building massing.2. Connection to the Street: Identify opportunities for the project to make a strong connection to the street and carefully consider how the building will interact with the public realm. Consider the qualities and character of the street-scape - its physical features (sidewalk, parking, landscape strip, street trees, travel lanes, and other amenities) and its function (major retail street or quieter residential street) - in siting and designing the building.**CS2.3 Adjacent Streets

a. Aurora and Dexter Avenues N: New development should help to make these arterials entries into downtown by implementing substantial landscaping and attractive building facades. Balconies and outdoor living spaces are less desirable facing these streets. Because these arterials will be primarily experienced by vehicle, the scale of street improvements and facade elements could be larger than if these streets were predominantly pedestrian-oriented.b. Eighth and Ninth Avenues N: Even though these streets may be occupied with several office buildings rather than residences, substantial landscaping and pedestrian interest should be emphasized along the street front. Courtyards and small open spaces may be more appropriate than a uniform street wall. h. Mercer Street: Mercer Street is the widest and most heavily used street in South Lake Union. Strong street walls on both sides of the street will enhance the street’s spatial characteristics. Ground floors should contain active building uses such as lobbies and group work spaces facing the corridor as well as retail and other pedestrian oriented uses. Ground floor spaces should be lit at night. Of special note is the ‘Teardrop Site’ at Broad Street, which provides opportunities for a number of special uses and activities.


The Slow Cut approach responds to the historic connection between Seattle Center and Elliott Bay and the old Broad Street diagonal pathway through the site. These patterns of movement are re-established on the Mercer Blocks site by lifting the podium of Mercer West, highlighting the importance of the recreation center, and creating the invitation into the Slow Cut in one grand gesture. At the civic scale, the buildings’ towers angle back to frame views from the Space Needle to Lake Union. At the pedestrian scale, the Slow Cut is created via the podium lift at Mercer West which provides increased space for an active 8th Ave public access easement and by the shaping of both buildings to reinforce physical and visual invitation into the site. These moves create a distinct building mass with identifiable architectural presence. At a medium and smaller scale, the preferred scheme responds to each bounding street’s different characters: boulevard/great streets (Dexter and Mercer), a classified woonerf street (Roy), a mixed use street (9th Ave N), and the heart of the Slow Cut concept (8th Ave N public access easement).

Mercer St: Gateway PresenceAs the largest and fastest edge of the site, Mercer St. requires a bold response to hold its urban presence while responding to a variety of modes of engagement.1- The tower anchors the gateway corner of Dexter and Mercer, then the podium is raised to mark a strong, but inviting street edge.2- The lift of the podium gives individual identity for the recreation center, communicating its importance as a highly public amenity in this development. The lift also provides a larger public space at the 8th Ave public access easement and an invitation into the Slow Cut. 3- A secondary massing fold creates a clear path into the Slow Cut, and the highly visible recreation center.4- While still holding the Mercer edge, the mid-tier, horizontal band reduces the overall scale of the Exchange by creating a series of terraces along Mercer. Cascading from the Hub, and from Seattle Center to the Lake, these terraces at the Exchange provide smaller scaled elements along the Mercer frontage.5- The ground floor horizontal volume folds to mark the entrance into the building, as well as to define the meeting space at the corner of Mercer and 9th.

Dexter Ave N: A main arterial connection to the north, the massing along Dexter is focused on encouraging urban activity and transition.1- The tower anchors the gateway corner at Dexter and Mercer, but peels back to introduce a change in scale. The reduction in scale along Dexter to Roy addresses the zone transitions from SM-SLU 175/85-280 to SM-UP and LR3RC to the west and northwest re-spectively. 2- The low podium face holds the street edge to reinforce the urban corridor with street activity. A landscaped terrace on the roof of the podium creates activity at multiple levels on the street edge, relating in scale to buildings along Dexter.3- The ground level steps back at the northwest corner to create an intimate scale, complementing the pedestrian facades along Dex-ter, while establishing a clear, distinct entry.

CS 2 (cont’d)


5

4

1

THE HUB

THE EXCHANGE

2

3

4

5

UW Phase 3

Allen Institute

UW Phase 2

601 Dexter


2

1

UW Medical

3


1


2

3

Mercer St

Dexter Ave

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6

5

DESIGN GUIDELINES

Roy St: Neighborhood ScaleRoy St. is the “slowest” of the edges, and is therefore focused on the experience of pedestrians and cyclists.1- At the Exchange, the ground-floor horizontal volume angles back from the corner of 9th and Roy as an invitation into the Slow Cut.2- The colonnade frames movement into the Slow Cut and, along with the bicycle parking entry, defines the plaza space between the building and Roy Street.3- The only vertical element- the northeast corner of the Hub tower- is a tall landmark that identifies a place to stop, and move through the 8th Ave public access easement and Slow Cut4- The Hub building folds inwards to create a transition in scale and greater landscape activity along Roy St, both at the ground plane and elevated terrace. At the base, this move highlights the entry and activates the Dexter & Roy cor-ner. The reduction in street front massing along Roy Street addresses the zone transition from SM-SLU 175/85-280 to SM-SLU 85/65-160.5- Two terraces at different levels create a secondary scale that relates to adjacent buildings and multiple points of interaction along Roy Street.

9th Ave: City ConnectorThe shortest edge on the site, 9th Ave spans between the quieter experience of Roy and the speed & activity of Mer-cer.1- The three horizontal volumes of Mercer East step back from Mercer to the corner of 9th and Roy marking the intro-duction into the Slow Cut from the lake.2- The ground floor volume folds back from Roy Street towards the 8th Ave public access easement as the invitation into the Slow Cut.3- With no “back door” to the overall property, the loading access is placed across from the Allen Institute’s back of house ground level facade.4- The lower podium at the south east corner is grounded by a meeting space that draws people from the north, south, and east of South Lake Union.

(See pages 86-91 for more information)

CS 2 (cont’d)

THE HUB

THE EXCHANGE

Allen Institute Dexter Yards

601 Dexter

615 Dexter

701 Dexter

1

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Roy. looking east

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THE EXCHANGE

9th Ave

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DESIGN GUIDELINES

CS 2 (cont’d)

C. Relationship to the Block

3. Full Block Sites: Break up long facades of full-block buildings to avoid a monolithic presence. Provide detail and human scale at street-level, and include repeating elements to add variety and rhythm to the facade and overall building design. Consider providing through-block access and/or designing the project as an assemblage of buildings and spaces within the block.**CS2.4.b. Full Block Sites: New developments often occupy half to full block sites, which can have street facades as long as 400 feet. Unmodulated or unbroken facades that long generally disrupt the smaller, historical pattern and pedestrian scale at the ground level, and create a blocky podium form when the building is viewed from afar. The zoning code limits the size of a building’s podium and towers, but these provisions don’t limit the development of expansive, full block-long facades.

1. Avoid internalized campus like developments with uniform architectural character. Large projects should express varied architectural elements and orient open spaces toward the streets and public realm.2. Building facades should be articulated with modulation, fenestration patterns, different materials, and/or other means so that the building podium is not a monolithic block. The articulation should extend to all stories in the podium. Horizontal and vertical modulation beyond code minimums that further breaks a building’s facade into legible elements, is encouraged.


The 8th Ave N public access easement and mid-block connection is the heart of the preferred scheme. As a three-dimensional public realm framing views on a civic scale and creating a diagonal, through-site passageway on a pedestrian scale, it is the connection both between the “Hub” and “Exchange” buildings as well as to neighborhood features like Lake Union, Seattle Center, and Denny Park. Its continuation of 8th Ave N emphasizes the pedestrian and activates the ground plane with small and medium scale design and programming, creating a cohesive but differentiated, varied, and active pedestrian experience through the project site.

At the Hub, Tower massing is peeled and modulated in support of the Slow Cut - angling into the 8th Ave public access easement to create grander public space, create an identifiable, connected place for the recreation center, and reinforce the Slow Cut axis from Lake Union to Seattle Center on the ground floor. Secondary connections through the public areas of the two buildings reinforce the Slow Cut diagonal movement. These place-making moves, enabled by the podium lift, breaks the building facades into legible, scaled elements.

Beyond the 8th Ave N public access easement relation, the “Hub” and “Exchange” buildings are different and specific in their responses to the immediate context. Programmed with the community rec center, the “Hub” expresses a large raised podium and cantilever to highlight and give massing prominence to the rec center fronting the 8th Ave N public access easement. The rec center’s sport court is a secondary massing scale that sits under the cantilever, a point of interest visible from Mercer, 8th, and Roy that activates the through block connection between Mercer and Roy. In response to its more public ground plane program, the “Hub”’s larger scale massing moves create a more civic environment in line with its distinct identity, recognizable even from a distance.

Conversely, the “Exchange” responds to its context in a less heroic manner. The building is scaled horizontally, creating three distinct levels responding to the larger context. The tower frames the slow cut, the mid-tier provides a medium scale and active outdoor terraces, and the ground-plane volume further breaks down through a series of horizontal breaks that mark entries, programs, and elevation changes.

The two towers have different design concepts but both support the larger Slow Cut approach through similar formal language.

The facade expression differentiates similarly to the massing. Solar orientation, views, and changes in neighborhood scale from North to South influence the scale of the expression of the facade as it wraps the buildings. Materials and textures will also change from building to building on the facade expression, further differentiating the two.

(See pages 82-93 for more information)

tower & podiumDistinct tower and podium elements sit atop one another. Massing is pushed off Mercer to provide relief to each street.

invitationTower reorients to reduce the scale of the building along Roy, while beginning to open up to the 8th Ave public access easement.

stackA ground level setback to 8th ave along the Slow Cut further breaks the building down into a stack of 3 distinct components: tower, podium, and base.

scaled terracesThe podium volume is shifted to create a number of scaled terraces. These terraces match adjacent datums around the site.

slow cutat Mercer West, the podium shifts vertically along the Slow-Cut to create varied & scaled urban rooms and a generous public space below. The recreation center sits prominently along Mercer engaging the 8th Ave public access ease-ment. The ground floor level at Mercer East breaks down in scale both horizontally and vertically, engaging people through varying levels, entries, and programs, in particular, at the 8th Ave. public access easement.

the Exchange

the Hub

the Hub

the Exchange

gatewayBaseline massing responds to the Gateway Corner of Mercer and Dexter. Holding a presence, and anchoring this corner, re-sponds to the neighboring context.

slow cut invitationTower reorients to reduce the scale of the building along Mercer, while beginning to open up to the 8th Ave public access easement.

liftPodium massing along Mercer and 8th Ave is lifted to define an urban room. This lift is critical to creating a high degree of porosity and transparency into 8th Ave.

activationAmplifying the highly public nature of 8th Ave, the recreation sport court is placed at the corner of 8th and Mercer, activating the Slow Cut while providing this urban amenity a presence to the city.

!

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SM-SLU175/85-280

SM-UP 85 (M)

SM-UP 95 (M)

SM-SLU100/95

SM-SLU85/65-160

UPTOWN URBAN

CENTER

SOUTH LAKE UNION URBAN

CENTER

Aurora Ave N

Dexter Ave N

9th Ave NW

estlake Ave N

Mercer St

8th Ave N

Roy St

9-Block Diagram w/ Preferred Massing

Capitol Hill

First Hill

Denny Hill

Queen Anne

Historic Topography and Watershed Arterial History (Google Aerial - 1990s)

CS 2 (cont’d)

CS 3 Architectural Context & Character

A. Emphasizing Positive Neighborhood Attributes

4. Evolving Neighborhoods: In neighborhoods where architectural character is evolving or otherwise in transition, explore ways for new development to establish a positive and desirable context for others to build upon in the future.

B. Local History and Culture

1. Placemaking: Explore the history of the site and neighborhood as a potential placemaking opportunity. Look for historical and cultural significance, using neighborhood groups and archives as resources.


The preferred scheme’s “Slow Cut” is based not only on providing present-day access between neighborhood features (Lake Union, Seattle Center, Denny Park), but also on historic watershed movement and Seattle’s arterial highway history that not too long ago occupied the project site. This “cut” acknowledges ecological and human history, present-day access, and hopefully serves as an impetus for future ground plane transparency and circulation. (see pages 26 and 27, 72-81 for more information)

D. Height, Bulk, and Scale

3. Zone Transitions: For projects located at the edge of different zones, provide an appropriate transition or complement to the adjacent zone(s). Projects should create a step in perceived height, bulk, and scale between the anticipated development potential of the adjacent zone and the proposed development. Factors to consider:

a. Distance to the edge of a less (or more) intensive zone;b. Differences in development standards between abutting zones;c. The type of separation from adjacent properties (e.g. separation by property line only, by an alley or street or open space, or by physical features such as grade change);d. Adjacencies to different neighborhoods or districts; adjacencies to parks, open spaces significant buildings or view corridors; ande. Shading to or from neighboring properties

4. Massing Choices: Strive for a successful transition between zones where a project abuts a less intense zone. In some areas, the best approach may be to lower the building height, break up the mass of the building, and/or match the scale of adjacent properties in building detailing. It may be appropriate in other areas to differ from the scale of adjacent buildings but preserve natural systems or existing features, enable better solar exposure or site orientation, and/or make for interesting urban form.


The project site sits at a transition between the smaller scale Uptown Urban Center to the west and the growing South Lake Union Urban Center to the southeast. It also sits adjacent to different zoning envelope regulations, with a maximum building height range of 85’ - 175’. In response to the zoning transitions, the “Hub” is a more civic response, with bolder massing moves, in acknowledgment of Gateway Corner at Mercer and Dexter. Along Dexter, the westernmost boundary of the site, the tower is set back providing better solar exposure along Dexter and Roy Street.

The Exchange’s three volumes modulate to allow better solar exposure to Roy and a general smaller scale building, acknowledging the zoning transition to the northeast. Also, the Exchange maintains a similar and related massing scale to the rest of South Lake Union’s precedents with a strong street wall presence along Mercer and clear base / mid-tier / tower legibility. (see pages 86- 93 for more information)

DESIGN GUIDELINESDESIGN GUIDELINES

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without proposed podium departure with proposed podium departure = 2.2x more open space @ ground + additional deck

Perspective Looking North on 8th Ave N public access easement

DESIGN GUIDELINES

PL 1 Connectivity

A. Network of Open Spaces

1. Enhancing Open Space: Design the building and open spaces to positively contribute to a broader network of open spaces throughout the neighborhood. Consider ways that design can enhance the features and activities of existing off-site open spaces. Open space may include sidewalks, streets and alleys, circulation routes, and other open areas of all kinds. 2. Adding to Public Life: Seek opportunities to foster human interaction through an increase in the size and/or quality of project-related open space available for public life. Consider features such as widened sidewalks, recessed entries, curb bulbs, courtyards, plazas, or through-block connections, along with place-making elements such as trees, landscape, art, or other amenities.**PL1.1 Network of Open Spaces: Open spaces in South Lake Union include mid-block connections, ground-level open space developed in new projects, and three parks: Denny Park, Cascade Playground, and Lake Union Park. Including green streets, Class I Pedestrian streets, and development of an open space network is a priority for the neighborhood. These spaces play a critical role in the transportation system and provide space for community activity.

a. Mid-Block Connections: Where possible, incorporate mid-block connections, linked courtyards, or activating alleyways. Consider merging different mid-block connectors to increase activity, such as an alleyway joined by a courtyard. b. Street-Level Open Space: For both retail and residential focus areas, consider private or semi-private courtyards facing the street, or pocket parks. c. Open Space Connections: Open space connections should respond to view corridors of neighborhood-scale and regional open spaces, such as the Seattle Center, Lake Union, Denny Park, and Cascade Playground. d. 8th Ave North: Create a visual and physical connection along 8th Ave between Mercer St and Roy St.


Street level open space is an important design driver for the design approaches and is made most clear in the preferred scheme. At the ground plane in the preferred scheme, both the “Hub” and the “Exchange” formally create the ‘slow cut’ pedestrian connection from Seattle Center to Lake Union - more than doubling the minimum required open space area along this connection.

The “Hub” emphasizes this connection and street-level open space by lifting its podium to provide more ground plane public space, additional activated deck area on top of the sport court overlooking the 8th Ave public access easement, and creating a three-dimensional, multi-tiered public realm experience. The “Exchange” angles back from 9th at Roy in order to create the invitation into the Slow Cut at a smaller, more residential scale. The “Exchange”’s tower, like that of the “Hub” angles from southeast to northwest to emphasize the Slow Cut at a civic scale.

The 8th Ave N public access easement is the heart of the project – the focus of activity and open space on the ground plane. The programmatic elements on either side of 8th reinforce this heart: the recreation center, amenity spaces, lobbies, and bicycle parking pavilion all open up and are accessed from 8th, creating an indoor-outdoor connection. In the floors above, terraces are created to maximize views to Lake Union and Seattle Center. The axial shift in the preferred approach makes the grandest gesture to the connection between Lake Union and Seattle Center and provides terraced outdoor space for views across South Lake Union. A landscaped walk continues the north-south connection across the easement, creating a legible pedestrian experiences.

(see pages 80-81, 106-113 for more information)

Dex

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Mercer St

Roy St

View A

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Seattle Center

Lake Union

Continued N-S connection

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protected bike lanes

protected bike lane NEW protected bike lane

bike entry

bike entry

Roy St

Mercer St

9th A

ve N

Dexter A

ve N

protected bike lane

bike storage / locker facilities(below)

bike storage / locker facilities(below)

Interior bike storage capacity across project site = 370 *locker / shower facilities located adjacent to interior bike storage

Exterior public bike racks across project site = 75

Bike Planning

Perspective Looking South Along 8th Ave N Public Access Easement

B. Walkways and Connections

3. Pedestrian Amenities: Opportunities for creating lively, pedestrian oriented open spaces to enliven the area and attract interest and interaction with the site and building should be considered. Visible access to the building’s entry should be provided. **PL2.2.b. Walkways and Pedestrian Interest: Visually engaging pedestrian walkways reinforce the pedestrian network and are an important element in project design. The pattern of near-by features, spatial changes, and points of interest define the pedestrian experience. In designing projects with exposure to pedestrian walkways consider the following guidance:

a. Points of interestb. Focal features - an open space, pedestrian connection, activity center, or significant variation in spatial enclosurec. A strong element at one end of a corridor can act as a ‘terminus’ by providing a destination or a view point that can be seen from the corridor. Similarly, a central plaza or landmark can attract pedestrians


In the preferred scheme, the public sport court and active spaces on the 8th Ave N public access easement have distinct massings that differentiate them and engage pedestrian interest on a more localized scale through smaller-scale massing proportions and higher detail and texture levels. The proposed podium lift in the “Hub” allows a village-type read to these massings, further engaging them with the pedestrian experience through visibility to sky and transparency across the easement.

Complementing the sport court and amenities along the Slow Cut, designed landscape elements and smaller outdoor rooms are arranged through the space to draw pedestrians into the project site and towards either Lake Union or Seattle Center. A linear north-south walkway connects to other 8th Ave N experiences, weaving the street grid together in a coherent pedestrian experience.

(see pages 102-111 for more information)

PL 1 (cont’d)


B. Planning Ahead for Bicyclists

1. Early Planning: Consider existing and future bicycle traffic to and through the site early in the process so that access and connections are integrated into the project along with other modes of travel. 2. Bike Facilities: Facilities such as bike racks and storage, bike share stations, shower facilities, and lockers for bicyclists should be located to maximize convenience, security, and safety.3. Bike Connections: Facilitate connections to bicycle trails and infrastructure around and beyond the project. Design bicycling access points so that they relate to the street grid and include information about connections to existing trails and infrastructure where possible.


The building site is bound with protected bike lanes on its east, west, and north by 9th Ave N, Dexter, and Roy St, respectively. To the south, a future protected bike lane will be constructed on Mercer as part of this project. Easy and separated access to the planned bike storage and locker room facilities will be located in both buildings. Separate, dedicated entrances on the ground floor of each building, independent of the main lobby, ensures a high degree of accessibility to bicycle storage.

The preferred approach currently locates bicycle parking entrances for both buildings to be located off of the designated green street on Roy, a safer street for pedestrians and cyclists. The lifted podiums also provide the opportunity for increased ground plane use - including more strategic public bike parking across the site. A larger concentration of public bike racks will be located off of the more public 8th Ave public easement, but racks of similar design will be placed throughout the site adjacent to entrances to further encourage active transportation.

DESIGN GUIDELINES

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amenity

lobby

lobby

meeting

spaceamenity

amenity

amenity recreationcenter

sportcourt

deck

ramp to

bike parking

mercer st

mercer st

roy st

roy st8thave

dexterave

9thave

bike parking

8th Ave public access

easement

DESIGN GUIDELINES


A. Building-Open Space Relationship

1. Interior / Exterior Fit: Develop an open space concept in conjunction with the architectural concept to ensure that interior and exterior spaces relate well to each other and support the functions of the development.**DC3.1.a - Interior/Exterior Fit: Locate open spaces toward streets with high pedestrian volumes and “Heart” locations. Open spaces accessible to the public should be visible from the street.

B. Open Space Uses and Activities

3. Connections to Other Open Space: Site and design project-related open spaces should connect with, or enhance, the uses and activities of other nearby public open space where appropriate. Look for opportunities to support uses and activities on adjacent properties and/or the sidewalk.

C. Design

1. Reinforce Existing Open Space: Where a strong open space concept exists in the neighborhood, reinforce existing character and patterns of street tree planting, buffers or treatment of topographic changes. Where no strong patterns exist, initiate a strong open space concept, where appropriate, that other projects can build upon in the future.


The “Slow Cut” concept in the preferred scheme connects the 8th Ave N public access easement through block movement to important neighborhood open spaces: Lake Union, Seattle Center, and Denny Park specifically. Its diagonal nature, enabled by the podium lift at the ‘Hub’ enlarges the open space along the 8th Ave N public access easement while connecting to the active ground plane programming fronting it.

While the walkway design and street trees along the 8th Ave N public access easement create the strong north-south connection along 8th Ave N to Denny Park, the Slow Cut introduces and integrates open space with the two buildings on the project site.

The small-scale pavilion volumes and active public spaces hosted by the “Hub” and “Exchange” further energize the larger open space. Additionally, the terraces on top of the pavilions as created by the podium lift and massing scale moves, extend the open space vertically, creating a three-dimensional experience.

(see pages 80-81 and 106-113)

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Mercer St.

8thAve.

9thAve.

The HubMercer West

The ExchangeMercer East


A. Massing

1. Site Characteristics and Uses: Arrange the mass of the building taking into consideration the characteristics of the site and the proposed uses of the building and its open space. In addition, special situations such as very large sites, unusually shaped sites, or sites with varied topography may require particular attention to where and how building massing is arranged as they can accentuate mass and height.2. Reducing Perceived Mass: Use secondary architectural elements to reduce the perceived mass of larger projects. Consider creating recesses or indentations in the building envelope; adding balconies, bay windows, porches, canopies or other elements; and/or highlighting building entries.**DC2.1 - Massing, Design, and Scale: Consideration of three scales. Buildings and their surroundings are perceived at three scales:

1) The pedestrian scale that relates to human activity within the immediate vicinity of the pedestrian (roughly 60 feet horizontally)2) The street space where the street and adjacent open spaces are perceived as a ‘room’ (generally street block or two long and about 60 feet high)3) Tall building or skyline scale (where the building form is perceived generally at more than a block away)

**DC2.2.a - Street-level Scale: Podiums in South Lake Union are intended to promote a pedestrian scale by creation a ‘street wall’ that is proportional to the width and intensity of the streets they face. Podiums lower three floors or less are limited to 75% lot coverage to promote creative massing within the constraints of the podium height limits. Towers that extend a building’s street front facade upward directly from the podium can diminish break up height and scale consistency of an otherwise coherent spatial ‘street room.’ For a successful scale transition, the podium facade should provide pedestrian scaled elements and proportions.

DESIGN GUIDELINES

**DC2.3 - Building Podiums: Podiums in South Lake Union are intended to promote a pedestrian scale by creation of a ‘street wall’ that is proportional to the width and intensity of the streets they face. Podiums lower three floors or less are limited to 75% lot coverage to promote creative massing within the constraints of the podium height limits.

a. Express Building Podiums: Commercial structures should express a podium level by stepping back a portion of the structure at the podium height limit.b. Street Wall Variation: Although podiums are required, it is important to achieve some variety in street wall height. Full block projects should explore creative massing at the podium level to achieve variety.

**DC2.4 - Tall Buildings: Tall buildings require additional design guidance since they are highly visible above typical ‘fabric structures’ and impact the public visual realm with inherently larger facade surfaces, bulk, and scale shifts. These Tall Building Guidelines work in concert with and do not restate applicable Citywide Guidelines (or applicable neighborhood guidelines), which cover many important topics on the base and lower levels of tall buildings.

a. Response to Context: Integrate and transition to a surrounding fabric of differing heights; relate to existing visual datums, the street wall, and parcel patterns. Respond to prominent nearby sites and/or sites with axial focus or distant visibility, such as waterfronts, public view corridors, street ends.


The preferred scheme’s two massings (“Hub” and “Exchange”) were driven by numerous factors: the atypical property boundary as a remnant of the historical highway, 8th Ave N public access easement through way, and Mercer St’s larger traffic volume in contrast to Roy St’s more residential scale.

In response to these factors, each building considers not just the three scales as defined by the design guidelines (pedestrian, street, and skyline), but a range of five distinct volume expressions (XS - XL) that transition from the pedestrian detail to the city skyline.

Each building’s massing concept responds to its context in a different way: the “Hub” through a more vertical, folded expression and the “Exchange” through a horizontal, volumetric design. All together, the various massing moves, scales, and transitions create an identifiable architectural presence and expanded public realm at a distinguished site.

XS: street-scapeThe Hub and the Exchange meet the ground with an intentional focus on the human scale. Street frontages are activated with programs that contribute to the neighborhood and enriched with opportunities to spill outside. Possibilities for articulation, materiality, canopies, and entry definition will further add a sense of tactility and vibrancy to the street experience.

S: pavilion programsThe recreation center sport court, child care, and the work lounge/ entry into bicycle parking act as “objects in the landscape”. Taking on a character independent of the towers, these programs define and anchor the ground plane, especially along the 8th Ave public access easement. Varying in scale, and potentially in materiality, the pavilions serve to add another layer of legibility to the ground plane. Along Mercer, the size and scale of the meeting space similarly creates a connection to South Lake Union.

M: folds and terracesAt The Hub tower facades are folded to respond to different conditions around the site: along Mercer St, the fold creates a sense of invitation into the Slow Cut, as well as bringing down the scale of the tower. Along the northern edge, this fold peels back the tower to minimize the presence along Roy, and allow more daylight into the street. At the Exchange, shifts in the horizontal stacking of elements create scaled terraces along all four streets. These terraces provide a legibility to the stacking, and bring down the scale of the building while providing activation and amenity.

L: shell and stacksAt the Hub, the massing responds to the Gateway corner of Mercer and Dexter with a continuous vertical face, connecting this gate-way from ground to sky, as well as to the adjacent context. This “shell” then wraps the entire building in a continuous, clear, and civic gesture. The neighborhood scale of the Exchange is more broken down. Tower, podium, and base are clearly articulated, breaking down the scale into distinct elements.

XL: anchored cornersThe project is defined by the Slow Cut. Starting at the Gateway Corner of Mercer and Dexter, the Hub tower angles into 8th Ave, defining the Slow Cut, and creating a much greater sense of invitation into the 8th Ave public access easement. At the Exchange, the tower massing also angles into 8th ave. Together this xl scale orientation of towers enhances the urban move of the Slow Cut.

(see pages 72-93 for more information)

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DEPARTURES

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DEPARTURES

Requirement Request

Departure #423.48.245.D.1Facade Modulation in SM-U Zones

Max length of unmodulated facade within 15’ of street lot for: • stories w/ specified podium height up to 145’ = 150’

Request for: • 225’ facade from height 84’ - 123’ for the Hub along Mercer St

Departure #123.48.025.C.7.bRooftop Features

No rooftop features are permitted to be located closer than 10 feet from the roof edge

Request to locate 2,630 sf rooftop features closer than 10 ft to the roof edge at the Hub ( west building)Request to locate 121 sf rooftop features closer than 10 ft to the roof edge and to extend coverage percentage from 65% to 79% at the Exchange ( East building)

Departure #2 23.54.030.B.2.cParking Space Size Proportions

Request for reducing the percentage of large vehicles spaces from 35% to 20%

Min. 35% parking spaces must be sized and striped for large vehicles

Departure #3 23.48.240.B.1.bLot Line Setback

Request to set back further than 12 feet for a total of 7,262 sf in various conditions across the project site. These further setbacks include provisions for required easements.

Except on Class 1 Pedestrian Streets, the street-facing facade of a structure may be set back up to 12 feet from the street lot line

Departure #523.48.245.B.4.aPodium Height

Per feedback from the City, podium height limit applicable at the development site is 85’

Request to raise the podium height: • from 85’ to 123’ from Dexter to 8th Ave along Mercer

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Rooftop section at the “Hub”

MW-1.560' - 0"

MW-150' - 0"

MW-P134' - 0"

MW-P225' - 0"

MW-P316' - 0"

MW-273' - 0"

MW-386' - 0"

MW-499' - 0"

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MW-11190' - 0"

MW-12203' - 0"

MW-13216' - 0"

MW-ROOF229' - 0"

MW AVG GRADE54' - 6"

SEA LEVEL0' - 0"

LAKE LEVEL18' - 0"

WATER TABLE20' - 0"

MW-P47' - 0"

MW-P5-2' - 0"

flight path

223 YALE AVENUE NORTHSEATTLE, WASHINGTON 98109PHONE 206 223 5555www.nbbj.com

SCALE

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23.48.025.C.7.bRooftop Features Coverage and Distance to Roof Edge

Design Standard:

At the applicant’s option, the combined total coverage of all features listed in subsections 23.48.025.C.4 and 23.48.025.C.5 may be increased to 65 percent of the roof area, provided that all of the following are satisfied: a. All mechanical equipment is screened; andb. No rooftop features are located closer than 10 feet to the roof edge.

Departure Request:

Request to extend coverage percentage from 65% to 79% at The Exchange

Request also to locate 2,630 sf rooftop features at “The Hub” and 121 sf at “The Exchange” closer than 10 ft to the roof edge, totaling 2,751 sf.

All rooftop features to be enclosed by an integrated screening around 100% of each building’s perimeter.

Rationale:

To support the program anticipated in the tower, rooftop features coverage is anticipated to be over the 25% allowed under 23.48.025.C.4. The Hub (western structure) will not exceed the 65% as allowed under subsection 23.48.025.C.7. The Exchange (eastern structure) is requesting an increase in coverage percentage to 79% to incorporate equipment related to the anticipated energy district (CS1.A.1 Energy Choices). Per SMC 23.48.225 Map A South Lake Union Seaport Flight Corridor, equipment height at the Hub is limited per the elevations shown, necessitating location of mechanical equipment closer than 10’ to roof edge. The proposed mechanical screen will be integrated into the facade materials and concept, tapering in height from 15’ to 2’ around the entire perimeter of the Hub’s roof edge and a consistent 15’ height around the entire perimeter of the Exchange’s roof edge so as to facilitate a better transition from building to sky (**DC2.4.j – Tall buildings – Transition to the Sky & Skyline Composition). Bringing the core and egress stairs closer than 10’ to roof edge also allows transparency opportunities at the egress stairs to provide visibility to activity within, both adding articulation and variation into the facade. (**DC2.5.a.2 – Secondary Architectural Features – Windows and Fenestration). At the western structure (Hub), locating the egress stair and associated core at the Mercer & Dexter corner also enhances the gateway impact of the building mass (**CS2.1.b – Urban Pattern & Form – South Lake Union Supplemental Guidance - Gateway Locations).

Supporting Guidelines:

• CS1.A.1 - Energy Choices• **CS2.1.b - Urban Pattern & Form - Gateway Locations• **DC2.4.j – Tall buildings – Transition to the Sky & Skyline Composition• **DC2.5.a.2 – Secondary Architectural Features –

Windows and Fenestration

departures | #1

flight pathstart of 15’ clearance under flight path

max 19’ under flight path

2’ min under flight path

elevator overrun, egress stair, 110 sf w/in 10’ setback

10’ offset from roof edge

10’ offset from roof edge

elevator overrun, mechanical equipment, egress stair, 2630 sf w/in 10’ setback

flight path

2’

15’

mechanical screen around entire perimeter of the Exchange, consistent 15’ tall

mechanical screen around entire perimeter of the Hub, sloping from 15’ - 2’ tall

mechanical yard extents

mechanical yard extents

potential green roof & terrace

egress stair, 11 sf w/in 10’ setback

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 133

23.54.030.B.2c Parking requirement, non-residential

Design Standard:

When 20 or more parking spaces are provided, a minimum of 35 percent of the parking spaces shall be striped for small vehicles. The minimum required size for small parking spaces shall also be the maximum size. A maximum of 65 percent of the parking spaces may be striped for small vehicles. A minimum of 35 percent of the spaces shall be striped for large vehicles

Departure Request:

Request for reducing the percentage of large vehicles spaces from 35% to 20%

Rationale:

The proposed parking design maximizes efficiency of the garage within the unique site geometry by efficiently consolidating all parking in a below-grade garage so that a great pedestrian environment can be created at grade. (**CS1.3.c – Natural Systems & Site Features - Conceal Underground Parking). The unique site geometry is compounded with the clearances to the King County Sewer Easements below grade, rendering parking planning efficiency more important. Increased parking efficiency within this limited area also enables possible additional stalls to support the more active public and pedestrian uses on the ground level such as the rec center, 8th avenue easement, and retail. All four streets bordering the project site have or will have protected bike lanes; keeping parking below grade with efficient planning further encourages non-automobile traffic and activity around the site (CS2.D.5- Respect for Adjacent Sites) (**PL4 – Active Transportation).


• **CS1.3.c – Natural Systems & Site Features - Conceal Underground Parking

• CS2.D.5 - Respect for Adjacent Sites• **PL4.A.1 – Active Transportation - Serving all

modes of travel

#2 | departures

MW-1.560' - 0"

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MW AVG GRADE54' - 3"

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WATER TABLE20' - 0"

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174'

- 9"

5' - 0 3/4"

TO M

ERCE

R TU

NNEL

EAS

EMEN

T5"

-9" C

LEAR

ANCE

MERCER TUNNEL

MERCER TUNNEL 10' CLEARANCE

LAKE UNION TUNNEL

LAKE UNION TUNNEL 10' CLEARANCE

FLIGHT PATH BEYOND MERCER EAST TOWER

9' - 6" MW-P4 BOTTOM OF SLAB

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110022448822..0000

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UP

DN

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DN

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8833


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SHEET ISSUE DATE

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B

SHEET OF 250

1 2

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C

D

E

3 4 5 6

1 2 3 4 5 6

F

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A

C

D

E

F

77//2277

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00 33::

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11//1166"" == 11''--00""

110022448822..0000

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IIssssuuee DDaattee

top of King County Mercer Tunnel vertical clearance top of King County Lake Union vertical clearance

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /134

Rec Center: Sport Court

8th

Ave

N

Publ

ic A

cces

s E

asem

ent

Mercer Street

Roy Street

Dex

ter A

ve N

9th

Ave

N

23.48.240.B.1.bLot Line Setback

Design Standard:

Except on Class 1 Pedestrian Streets, the street-facing facade of a structure may be set back up to 12 feet

Departure Request:

Request to set back further than 12 feet for a total of 7,262 sf in various conditions across the project site. These further setbacks include provisions for required easements.

Rationale:

Three easements affect the 12 foot setback: the 8th Ave public access easement, an 80’ diameter King County Sewer Easement, and the 9th Ave right hand turn easement. Beyond provisions for those easements, building entrances for the “Hub” are set back to provide weather protection and pedestrian scale on Dexter and Mercer, both Class II Pedestrian Streets (**PL2.1.a – Walkability - Weather Protection). The Roy St setback for the “Exchange” creates an enhanced bike entrance for the building as well as an area for bio-retention and filtration. Together with the “Hub’s” Mercer entrance, these emphasize transparency in the public ground plane diagonally across the project site, reinforcing the “slowcut” connection. With the Mercer St setback, the rec center sport court becomes a focal feature as a pedestrian invitation from Mercer. These setbacks create not just pedestrian interest but also an activated walkway and experience throughout the project site towards Lake Union (**PL2.2.b – Walkability - Walkways and Pedestrian Interest).

The continuity of those setbacks also builds an integrated open space across the site so that the design of the two buildings and the 8th Ave easement complement each other (DC3.1.a - Building Open Space Relationship). All of the setbacks proposed in the preferred scheme will be landscaped and contribute to the network of open spaces around the project site and surrounding neighborhood (PL1.A - Network of Open Spaces).


• **PL2.1.a - Walk-ability - Weather Protection• **PL2.2.b - Walk-ability - Walkways and Pedestrian Interest• DC3.1.a - Building Open Space Relationship• PL1.A - Network of Open Spaces

departures | #3

Property Line

12’ Setback from Property Line

allowable setback increased by 18’ maximum for 445 sf;• emphasizes transparency

diagonally across project site • distinguishes building

entrance

King County Sewer Easement

allowable setback increased by 60’ for 4,204 sf• emphasizes transparency

diagonally across project site • provides enhanced access for

bike entry off of Roy Street

allowable setback increased by 12’ for 28 sf • King County Sewer easement

provisions

allowable setback increased by 33’ for 541sf• distinguishes building entrance

off of Dexter and Roy corner

The Hub

The Exchange

allowable setback increased by 12’ maximum for 434 sf;• SDOT easement provisions

allowable setback increased by 62’ maximum for 840 sf;• emphasizes transparency

diagonally across project site • distinguishes building

entrance for rec center

allowable setback increased by 23’ maximum for 757 sf;• better emphasizes gateway

presence in response to 601 Dexter

allowable setback increased by 3’ maximum for 13 sf;• distinguishes secondary

building entrance off of Dexter

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 135

23.48.245.D.1Facade Modulation in SM-U Zones

Design Standard:

Maximum length of unmodulated facade within 15’ of street lot line for stories above the specified podium height up to 145’ is 150’ .

Departure Request:

Request for- 225’ unmodulated facade from height 84’-123’ for The Hub along Mercer St.

Rationale:

The proposed Hub design pushes massing vertically along the slow cut to create a scaled outdoor “room” engaging with 8th Ave. The volume establishes a podium datum for the Hub at 123’, matching the height of the UW Medical Campus immediately across Mercer (**DC 2.4 Response to Context). By allowing this volume to read consistently around Mercer St. to the 8th Ave public access easement, the podium becomes clearly defined and legible. (**DC 2.3 Expressed Building Podiums) The podium rooftop is designed as a terrace amenity. By maintaining the datum, more flexibility and usable space are able to be accommodated, improving the experience both for the users as well as surrounding developments with a view. (DC 2.5 Rooftops). Finally, the continued podium and terrace read in conjunction with the “fold” creating an intentional and integrated design when seen at a larger scale. (**DC4.i. Quality & 6th Elevations)


• **DC2.3.a – Expressed Building Podiums• **DC2.4.a- Response to Context• **DC5a.1- Secondary Architectural Features- Rooftops• **DC4.i.- Quality & 6th Elevations

#4 | departures

Code Compliant Proposed Departure The Hub from Mercer St.

150’

total area:450 sf/ floor= 1,350 sf

107’ 8”(< 120’)

113’ 2”(< 120’)

150’

225’

84’ 84’

123’

30’

15’

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /136

departures | #5

23.48.245.B.4.aHeight Limit for Podiums

Design Standard:

Per feedback from the City, the podium height limit applicable to this development site is 85’

Departure Request:

Request to raise the podium height at The Hub- from 85’ to 123’ from Dexter to the vacated 8th Ave N along Mercer

Rationale:“Slow Cut”: The proposed design is defined by the Slow Cut through the site, a highly activated, street level open space with visual and physical connections diagonally across the site. The proposed podium departure supports this in three distinct ways:

Enhanced 8th Ave Public Access EasementAt the center of the slow cut is the 8th Ave public access easement. The Slow Cut expands this key public space into a through-block connection diagonally across the site, providing 2.2x the required open space. (PL1.A.2 Adding to Public Life)In addition to the physical expansion of the public realm, it also increases the visibility, activity, and connection across 8th Ave by lifting the podium mass off of the ground plane. (**PL1.1 Network of Open Spaces) This lift allows for view corridors into 8th Ave from the Gateway Corner of Mercer and Dexter (**PL1.1.d. 8th Ave N). Additionally, from within 8th Ave, the podium lift and recreation center sport court frame a pedestrian view of the Space Needle (**PL2.2.b Focal Features), thereby reducing the perceived size of the Hub building at the ground plane (DCA.2 Reducing Perceived Mass). Lastly, the three-dimensional volume of the lift allows for activation of 8th Ave from multiple levels, by providing additional occupiable roof space from under the proposed cantilever & soffit. (**PL1.1.b. Street Level Open Space, **PL1.1.c. Open Space Connections)

Sense of Place and Recreation Center IdentityA key program element to the Hub building is a proposed recreation center. The proposed slow cut strategically locates the recreation center and its sport court program element, prominently along 8th ave, allowing it the capacity to engage further with the public realm and define a truly civic space. (CS2.A.1 Sense of Place) The proposed departure, in lifting the podium element, creates a 60’ tall “urban room” volume within which the recreation sport court is able to sit prominently, but with a character independent of the towers behind. Holding up to the scale of Mercer and the Gateway Corner, this move provides a presence to the recreation center that clearly denotes its importance, both to 8th ave, and South Lake Union. (CS2.A.2 Architectural Presence)

Response to Context and Scale The top of the proposed podium level is 123’, engaging with UW buildings across Mercer. (**DC2.4.a Response to Context), The Hub building is more boldly civic, whose podium departure creates a 60’ tall “street room” that responds to the scale of Mercer St and announces the identity of the rec center program at a smaller scale. (**DC2.1 Massing, Design, and Scale). The smaller sport court mass along Mercer not only creates a distinct and independent public identity, but a more transparent ground plane with frontages that vary the street wall height (**DC2.2.a Street-level Scale, **DC2.3.b Street Wall Variation).

!

sense of place and recreation center identityThe proposed podium lift defines a highly civic, accessible, public 8th Ave public access easement, while providing a volume within which the recreation center can achieve its own architectural identity.

Code Compliant Podium Height

CS 2.A.1 Sense of PlaceRecreation center sits prominently on, and is entered, off of 8th ave, integrating and enhancing the public realm

the Hub ( Mercer West) from the Exchange ( Mercer East) terrace looking west

CS 2.A.2 Architectural Presence

The sport court volume, sited prominent-ly on 8th and Mercer, defines an accessi-

ble, inclusive 8th ave, and distinguishes the recreation center from the tower.

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 137

#5 (cont’d) | departures

DC 2.1.2Massing Design and scale

The sport court volume provides a change in scale across Mercer, compli-

menting and contrasting the larger more civic moves at the Gateway Corner.

CODE COMPLIANT60’ wide urban canyon

PUSHto widen public access along 8th

LIFTto extend ground and identify transparent sport court

SCALEterracing at the Exchange in response to the proposed departure

enhanced 8th ave public access easementBoth the Hub (Mercer West) and the Exchange (Mercer East) actively work towards enhancing the public realm along the 8th Ave public access ease-ment. Improving on the required 60’ urban canyon, the Hub’s podium is pushed back to provide a physically wider space. Next, the lower three floors of the podium are lifted to create a 120’ wide volume at the ground, physically doubling the extent of 8th ave. A shift of the podium within the Exchange building again defines a lower scaled element along 8th Ave, and expands the perceived space of the public realm.

Code Compliant

Code Compliant

Departure Request


2

1

UW Medical

3

response to contextThe proposed departure lifts the podium along 8th and Mercer specifi-

cally to a height of 123’, framing a contextual street edge along Mercer with the UW Campus.

no identityRecreation center appears to be part of the tower: a building amenity as opposed to public anchor.

architectural presenceThe lift allows the recreation center sport court to take on a distinct, independent, architectural identity, and integrating itself with the 8th Ave public access easement

DC 2.4.a Response to Context

Matching the existing height of the UW Campus contextualizes the departure

within the existing SLU context.

PL1.A.2Adding to Public LifeThe proposed departure lifts massing off of the ground plane, effectively doubling the size and quality of the 8th Ave public access easement

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /138

CODE COMPLIANT PROPOSED

85’

L13- Tenant

Roof

L12- Tenant

L11- Tenant

L10- Tenant

L9- Tenant

L8- Tenant

L7- Tenant

L6- Tenant

L5- Tenant

L4- Tenant

L3- Tenant

L2- Tenant

L13- TenantL12- Tenant

L11- Tenant

L10- Tenant

L9- Tenant

L8- Tenant

L7- Tenant

L6- Tenant

L5- Tenant

L4- Tenant

L3- Tenant

L2- Tenant

standard Hub

L1- Lobby / Rec Center

85’ Podium Height per Feedback from City

54’4”Avg Grade

19’

175’

Roof

175’

85’

123’

60’

L1- Lobby / Rec CenterOutdoor Space

proposed Hub

8th Ave. Public Access Easement

Dexter Ave.8th Ave. Public Access Easement

Dexter Ave.

Sport Court

38’

Roy St

Dex

ter A

ve N

9th

Ave

N

Mercer St

Dex

ter A

ve N

9th

Ave

N

Mercer St

Roy St

ground floor extents17,963 sf open space

ground floor extents40,259 sf open space =

2.2x increase

Request to Raise Podium Height 85’ to 123’ along Mercer St

A

A A

The Hub

departures | #5


(PL1.A.2 Adding to Public Life)(**PL1.1 Network of Open Spaces) (**PL1.1.d. 8th Ave N)(**PL2.2.b Focal Features)(DCA.2 Reducing Perceived Mass).(**PL1.1.b. Street Level Open Space)( **PL1.1.c. Open Space Connections)(CS2.A.1 Sense of Place) (CS2.A.2 Architectural Presence)(**DC2.4.a Response to Context)(**DC2.1 Massing, Design, and Scale)(**DC2.2.a Street-level Scale, **DC2.3.b Street Wall Variation).

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 139

#5 (cont’d) | departuresPL1.1Network of Open Spaces The Slow Cut envisions 8th ave at the heart of a larger, urban scale, through block connection.

PL1.1.d8th Ave N

The podium lift and recreation center sport court transparency allow for sub-stantially increased views into 8th Ave

from Mercer and Dexter.

PL2.2bFocal FeaturesThe proposed cantilever frames views of the Space Needle from 8th Ave.

PL1.1.cOpen Space ConnectionsThe proposed cantilever affords opportu-nities for activation at multiple levels.

DCA.2Reducing Perceived Mass

The gap between the soffit of the proposed cantilever and sport court roof

serve to reduce the perceived mass of the building.

Roy St

Dex

ter A

ve N

9th

Ave

N

Mercer St

The Hub

1 2

3

4

5

12

3

4

5

Aerial from Lake Union looking south

8th and Roy looking south

The Space Needle and Sport Court from 8th Ave

Across Mercer looking north

Aerial from Mercer look-ing north

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /140

08

APPENDIX

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 141

10.21.2020 / #3036395-EG / EDG / 816 MERCER/ /142

APPENDIX

Block 45NBBJ

Amazon in the RegradeNBBJ

Project SNBBJ

816 MERCER / EDG / #3036395-EG / 10.21.2020 / / 143

APPENDIX

400 DexterAlexandria

Bill & Melinda Gates FoundationGGN

University of Washington School of MedicineGGN

816 MERCEREarly Design Guidanceproject # 3036395-EG816 Mercer Street714 W. Mercer StreetSeattle, WA 98109

10.21.2020

| 800 MERCER LLC

816 MERCER - Seattle.gov

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