Future buildings…..3 Bed Semi detached case study - Passive ...

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Future buildings…..3 Bed Semi detached case studyNearly Zero Energy Building(NZEB), and the CostsDr. Shane Colclough

Dip EE, BSc, MIE, MBA, PhD, MIEI, CEng, EurIng

Ulster University

[email protected]

ulster.ac.uk

The Passive House….., the Nearly Zero Energy Building(NZEB), and the Costs

Dr. Shane Colclough


Ulster University

[email protected]

ulster.ac.uk

The Passive House, the Nearly Zero Energy Building (NZEB)……..

Dr. Shane Colclough


Ulster University

[email protected]

ulster.ac.uk

The Passive House, the Nearly Zero Energy Building (NZEB), and the Costs

Dr. Shane Colclough


Ulster University

[email protected]

ulster.ac.uk

The Passive House….., the Nearly Zero Energy Building(NZEB), and the Costs

Architects: Bott, Ridder, WestermayerPrivately financed project,

Additional costs subsidized by the State of Hesse

Dr. Wolfgang Feist

1996Passive House Institute

Today50,000+ Worldwide

19911st Passive House built

What is a Passive House: Genesis

Sustainability

Costeffectiveness

Comfort

PassiveHouse

Standard

Buildingsbuilt

better

Flexible, straightforward and open to all

What is a Passive House: Objective

A Passive House is a building in which thermal comfort [ISO 7730] can be guaranteed by post-heating or post-cooling the fresh-air flow required for a good indoor air quality without additional recirculation.

Climate independent Passive House definition

What is a Passive House: Definition

What is a Passive House: The Maths..(Where does the 10W/m2 come from?)

• Specific Heat Capacity of Air: 1.005kJ/Kg.K

• Density of Air: 1.205 kg/m3

• SHC per m3: 1.211 kJ/K

• For wall height of 2.5m & ach-1 of 0.5, 1.3m3 of air is exchanged each hour allowing 1.81 kJ/K of heat to be transported by air per m2 of floor area (0.42W/Km2).

• Assuming a lift of 25°C is possible (avoiding dust scorching), the max amount of heat transferable by air is 10W/m2.

*all based on treated floor area

**including (DHW, heating, cooling, auxiliary & household electricity)

Heating demand 15 KWh/(m²yr)

OR Heating load 10 W/m²

Cooling demand 15 KWh/(m²yr)

OR Cooling load 10 W/m²

Airtightness n50 0.6ac/h

Primary energy demand 120 KWh/(m²yr)**

Passive House criteria*

What is a Passive House: Criteria

11

1 Thermal

insulation:

U 0.15 W/(m²K)

Uw 0.8 W/(m²K)

33-pane glazing:

Ug 0.8 W/(m²K)

g-value 50 - 55%

4Airtight

envelope

n50 0.6 /h

5 Ventilation with heat

recovery 75%

outside air waste air

supply airexhaust air

2 Avoid thermal

bridge effectsa 0.01 W/(mK)

What is a Passive House: Typical Approach

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The Passive House…..,√ the

Nearly Zero Energy Building(NZE√√B), and the Costs

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The Passive House, the Nearly Zero Energy Building (NZEB)……..

Source: Department of Environment, Community and Local Government. ‘Towards Nearly Zero Energy Buildings in Ireland, Planning for 2020 and Beyond. November 2012

RoI National Targets for NZEB

• Passive House ‘appears’ to perform worse than NZEB

• Reality is different – PH is already NZEB

Advancement in Energy Efficiency in Republic of Ireland

Passive House max, including plug loads = 120 kWh/m2.year

Passive House max, excluding plug loads = ~ 60 kWh/m2.year

Primary Energy in kWh/m2.year

Passive House typical, excluding plug loads = ~ 40 kWh/m2.year

Source: Department of Environment, Community and Local Government. ‘Towards Nearly Zero Energy Buildings in Ireland, Planning for 2020 and Beyond. November 2012

• Passive Houses

• Prevailing Min Building

• Regulations

• nZEB Houses

Location of Case StudynZEBDwellings

Bennett Passive House and NZEB Case Study

Case Study Dwelling: Plans

• 3 bedroom,

• 2 story

• semi-detached

• house,

• floor area of 103m2

Case Study Dwelling: Elevations

• Sales price

• €190,000

• Starter Home

• Social Housing

Case Study nZEB Dwelling

• Photograph

20

Bennett Passive House DEAP Output

37.7

8.2

0.2420.250

DEAP

• Project Already Exceeds NZEB Requirements according to DEAP

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Key Message: Dwelling designed to Passive House standard is nZEBcompliant

PHPP Model Output

Bennett Passive House Normal PHPP Output

37.7

8.2

0.2420.250

DEAP

112

29.2

N/RN/R

Normal PHPP

• ‘Passive House’ Appears to Fail NZEB Miserably???????

Basis of Calculations of Primary Energy Demand {kWh/M2a}

Passive House

• Net Floor Area (TFA)

• Prim energy conv factor of 2.6

• All consumed energy

nZEB (Republic of Ireland)

• Gross Floor area

• Prim energy conv factor of 2.1

• DHW & Space Heating, fixed lighting & ventilation (omits egcooking, washing & clothes drying, entertainment eqpt, home office)

10%

24%

50%

24.24

5.26

0.1590.165

DEAP

Bennett Passive House ‘DEAP’ PHPP Output

91.1

18.6

N/RN/R

Normal PHPP

• ‘DEAP’ PHPP adjusted to omit plug loads, include PV production and reduce Primary Energy factor for electricity from 2.6 to 2.19

42.4

5.8

N/RN/R

‘DEAP’ PHPP

• Bennett Passive House Already NZEB

Other Factors Not Considered

DEAP Model PHPP Model

Floor area calculation Gross Net (“Treated Floor Area”)(excludes internal walls and stairs)

Winter Interior Temperature

~ 18.5OCAverage based on typical Irish dwelling layouts for 8 hrs per day

20OC throughout

Summer Interior Temperature

Overheating not predicted

25OC Max for 10% of year

Radiant Temperature Asymmetry

Not considered Avoided

Unintended air infiltration

< 7 m3/m2/hr @ 50Pa < 0.6 ach-1 @ 50Pa

Ventilation rate To be specified 15m3 fresh air per person per hour

Basis for model Benchmark house Bespoke model for each design

Validation of performance

Unpublished Scientifically validated

Heating duration 8 hours per day 24 hours per day

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Key Message: PHPP and RoINational Dwelling Energy Assessment Procedure are fundamentally different

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Key Message: Initial indications:Dwelling is performing in line with PH and DEAP expectations

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The Passive House, the Nearly Zero Energy Building (NZEB), and the Costs

Building to the passive house

standard compared with the

prevailing building regulations

The historical cost differentials

2000 (single dwelling) €18,010

2010 (scheme) € 4,000

2020 (scheme) ?

Analysis Aim

Examine the construction cost of building a

BER A3 house (current Requirement) in

comparison to an nZEB (BER A1 house).

Analysis applies to a housing scheme of 12

houses, and not a single house project.

32

33

nZEB (BER A1) Specification

34

Current Regs (BER A3) Specification

Parametric comparisonEnergy influencing elements

Item A3 A1

Thermal Envelope

{W/m2K} {W/m2K}

Insulation U Value Roof 0.16 0.07

Floor 0.21 0.08

Walls 0.21 0.17*

Windows & Doors 1.24 0.74

Ventillation system

Natural Ventilation Heat Recovery Ventilation

Heating System Main Oil Fired Central Htg

2 x 550W Electric rads

2 x 175W Towel rads

Backup & Multifuel Stove & air post heater

DHW

Immersion Heat Pump

Cost Comparison:2015 & nZEB (A1)Building Regulations

•Only building elements influenced by an energy aspect are examined.

•Company overheads or profit margins have not been included in the analysis.

•VAT has not been added on to the final figure.

•All costs figures quoted are at 1 Jan 2017.

•detailed base costs produced independently

of the developer

Basis of CalculationsA1 to A3

A1 house has been costed

What savings could be made by building to the A3

standard?

Analysis:

Quantity Surveyor from Building Firm

Quantity Surveyor from Waterford Institute of Technology

Researcher Ulster University

Overview: A1 to A3 Comparison

1. Preliminaries (Site Overheads)

2. Thermal Envelope-Substructure

3. Thermal Envelope-Superstructure

4. Windows and External Doors

5. Ventilation and Heating

38

€ 2,265.00

€ 715.00

€ 3,170.00

€ 900.00

€ 2,650.00

€ 130.00

Red = Additional CostBlack = Savings

39

Net Additional Cost of a A1 nZEB

dwelling Vs current B Regs is Zero!

Some conclusions: builders

perspective

Knowledge is essential.

Very few snags on completion.

Operator Manual is essential.

BER A1 House - Quicker turnaround

Highest standards are cost achievable.

On the drawing board…

The formula rolls out further….60 Houses built to the PH standard in Dublin

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Acknowledgements

Seamus Mullins, Michael Bennett Group, QS Michael Bennett, Michael Bennett GroupJohn Mernagh, Derrek Sinnott, WIT, QSProf Philip Griffiths, Prof NJ Hewitt

ulster.ac.uk

The Passive House, the

Nearly Zero Energy Building

(NZEB), and the Costs

Dr. Shane Colclough


Ulster University

[email protected]

ulster.ac.uk

Future buildings…..3 Bed Semi

detached case study

Nearly Zero Energy Building

(NZEB), and the CostsDr. Shane Colclough


Ulster University

[email protected]

A1 to A3 Comparison

1. Preliminaries (Site Overheads)

Additional Costs for A3

Increase in length of programme bar chart €2,750.00

Planning Contributions discount € 225.00

€2,975.00

Cost Reductions for A3

PHPP Fee (Passive House) € 540.00

Door Blower Test € 170.00

€ 710.00

Net Additional Cost to A3 €2,265.00

A1 to A3 Comparison

2. Thermal Envelope- Substructure


Provide chimney stack base

Reduced cold bridging detailing € 10.00


Reduction in insulation (230mm-80mm) € 725.00

Net Cost Reduction to A3 € 715.00

A1 to A3 Comparison

3. Thermal Envelope- Superstructure

Additional Costs for A3 Nil


Reduced cold bridging detailing €1,384.00

Reduced structure and insulation €1,786.00

Net Cost Reduction to A3 €3,170.00

A1 to A3 Comparison4. Windows and External Doors


Double Glazed windows and doors

(U Value 1.20W/m2K) €3,300.00


Triple Glazed windows and doors

(U Value 0.80W/m2K) €4,200.00

Net Cost Reduction to A3 € 900.00

A1 to A3 Comparison

5. Heating and Ventilation


Natural Ventilation, OFC Heating, Builders

Work, Chimney Stack, Stove and hearth €11,398.00


Omission of Nilan Unit, ducting system,

lagging, insulation. € 8,748.00

Net Additional Cost to A3 € 2,650.00

Future buildings…..3 Bed Semi detached case study - Passive ...

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