GOING GREEN AND STAYING GREEN

GOING GREEN AND STAYING GREEN 2012

GOING GREEN AND STAYING GREEN

(THE ARCHITECT’S ROLL IN NIGERIAN CONTEMPORARY ARCHITECTURE)

ABSTRACT

Man’s activities in the quest for technological advancement and comfort, has continuedto threaten man’s own life and environment at large. Research shows that constructionactivities have continued to increase geometrically with the increase in economicgrowth and urbanization, and contributes heavily to environmental degradation. It isalso obvious that rural urban migration has left our cities choked with people, while theincreasing rate of banking and industrial activities, have left people with no option thanto spend about 90% of their time indoors, with poor air quality and completely cut offfrom the exterior. This write up therefore, seeks to furnish us with possible ways bywhich architecture can help preserve the eco-system, improve occupants health andproductivity, reduce maintenance/replacement costs over the life of a building andconserve energy within a building, by the choice of materials used for construction andsimply working with nature, rather than against it. The paper analysis green buildingmaterials and criteria for selecting sustainable materials.

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INTRODUCTION

The term ‘green, or sustainable, or organic’ architecture has experiencedrapid growth andmaturity over time inthe last 10 years. Asits name implies, itcame about as a resultof the rising depletionand degradation of theozone layer and the eco-system, due to man’scontinuous industrial,construction andcommercial activities.The origin of the greenarchitecture movements

stems back to the green political movement. Key events includethe energy crisis of the 1970’s, the formation of the Greenpeaceorganization in 1971, as well as conception of the Green Party inEuropean and United States governments during the 70’s and 80’s.These events, Made stake holders more conscious of thedebilitating effects that our industrial society was having on

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CII Soharabji Godrej Green Business centre,Hyderabad. (photo from: www.greenbuildings,com)


the environment. Also, as a result of increase in industrialactivities in cities, it was observed that the average person,spends about 90% of their time indoors, and indoor air quality isabout four times worse than outdoors. The awareness of all these,trigger the minds of concerned professionals in the buildingindustry, to source ways to improving the air quality of theindoors and as well protect and preserve the natural environment,by adequately analyzing the site’s climatic conditions anddesigning to be in tune with nature, carefully selecting buildingmaterials that are renewable, incorporating and integrating tothe inside part of the outside. This new trend in design broughtabout energy efficiency in buildings, low long term cost ofmaintenance and enormous improvement in the efficiency ofoccupants while also adding value to the environment and thelocal community from where the particular material is sourced.Hence the concept of green architecture has become synonymouswith environmental sustainability, energy efficiency andrenewability, human comfort and efficiency.

THE CONCEPT OF GREEN ARCHITECTURE

A common assumption in recent years is that, the builtenvironment will necessarily degrade the natural environment. Butfor most of earth’s history, structures built for shelter havetypically enhanced bio-diversity and benefited the surroundingcommunity (Alexis Karolides). The term ‘GREEN ARCHITECTURE’, issynonymous with ‘SUSTAINABLE DEVELOPMENT’. Sustainabledevelopment has been defined, none too precisely, as ‘developmentthat meets the needs of the present without compromising theability of future generations to meet their own needs’ (RandallThomas 2006). In one of her write ups, Mrs. Zigisha Mhaskar,

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defined Eco-caring/Green building as one which encompasses the use ofclean energy, renewable energy, efficient use of water, use ofrecycled or recyclable materials and provides healthy indoor airquality. The Encarta dictionary defines sustainable developmentas: “the economic development maintained within acceptable levelof global resource depletion and environmental pollution”. Italso defined green as: that which is made with littleenvironmental harm, and produced in an environmentally andecologically friendly way, for example by using renewableresources. Hence, green architecture is the art and science ofdesigning and constructing energy efficient and eco-friendlybuildings, by the use of renewable/organic building materials andthe incorporation of nature. Green building materials arecomposed of renewable, rather than nonrenewable resources. Greenmaterials are environmentally responsible because impacts areconsidered over the life of the product (Spiegel and Meadows,1999). Green building is a way of enhancing the environment. Doneright, it is beneficial to human well being, community,environmental health and life cycle cost. This means tailoring abuilding and its placement on the site to the local climate, siteconditions, culture and community in order to reduce resourceconsumption, augment resource supply and enhance the quality anddiversity of life.Green building is not just an assemblage of environmentalcomponents. It involves analyzing such interconnected issues assite and climatic considerations, building orientation and form,lighting and thermal comfort, and optimizing all these aspects inan integrated design. Green design elements, may each serveseveral functions and allow other building components to bedownsized. For example, better windows and insulation can allowfor smaller heating systems, photovoltaic panels can double asshade for parking or can replace a building’s spandrel glazing.However, green architecture, is more of a philosophy than itsstyle. It has no characteristic “look”.

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KEY BUILDING MATERIALS AND THEIR BASIC CHARATERISTICS

Different periods of history till date, have been characterizedwith different building materials, which made up the style ofthat particular period. The Hellenistic period of Greekarchitecture for instance, was possessed by building materialssuch as wood, unbaked brick, limestone and marble, terracotta(baked clay), and metals, especially bronze, used for somedecorative details. The Roman Empire on its part, were known withbricks, marble, stucco, gleaming white stone, and in the 1st

century AD, the Romans made a great use of concrete. Modernarchitecture is known for its development in two materials ofiron and concrete. Other building materials like straw, adobe,bamboo, stone and thatch, have been used as building materialsfrom antiquity. In our present age, different building materialsare in use irrespective of their availability, to archive thedesigner’s intent and purpose for which the structure is erected.Some of which include; platinum, fiber glass, high tech steel,ceramic, pvc materials, aluminum and pop.

LIMESTONE: - limestone is possibly the most widespreadbuilding material gotten via mining. Most often used ascladding material and in the production of other steel andglass. The burning of limestone after been crushed createssulfide emissions, a major contributor to acid rain. It isprimarily calcium carbonate until after conversion toquicklime on prolonged exposure to high heat, also calledcalcium oxide.

STEEL: - steel, requires the mining of iron ore, coal,limestone, magnesium, and other trace elements. To producesteel, iron must first be refined from raw ore, then bycontrolling the amount of carbon in iron, through furthersmelting. Limestone and magnesium are added including

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other metals like nickel and chromium which are relativelyrare and difficult to extract from the earth crust.

ALUMINUM: - aluminum is derived from bauxite ore andrequires a large amount of raw materials to produce asmall amount of its final product. Its manufacturing isalso a large consumer of electricity which is generatedfrom the burning of fossil fuel. The material is heated toalmost 3000F for this process to occur. Lots of waste isalso incurred in the process (called “mud”), containingtraces of heavy metals and other hazardous substances.“potliner” its byproduct contains fluoride and chlorineand must be disposed of as hazardous waste.

BRICKS AND TILE: - Clay and adobe soil must also be mined.They are usually found in shallow surface deposits, andmanufacturing is often done nearby, in order to reduceextraction and transportation costs. With the concessionof adobe, bricks and tiles must be fired to be usefulbuilding materials. The firing process exposes the formedclay to high, prolonged heat, producing a hard,waterproof, permanent brick or tile. This process takescouple of hours or even days and requires a large amountof energy. Even without firing, properly maintained adobebricks can out live 2 centuries.

PETROCHEMICALS: - The building industry is highlydependent on materials derived from petroleum and naturalgas. These are used in a wide range of products includingplastics, adhesives for plywood and particleboard,laminated countertops, insulation, carpeting, and paints.Drilling for oil and gas is both hazardous and expensive.Heavy machinery is required, and contamination of thegroundwater and soil is common.

Wood: - Wood is the harvested material most commonly usedin buildings and building products. It is a hard, toughsubstance that forms the trunks of trees. Wood productssuch as plywood, particleboard, and paper are usedextensively throughout the construction industry because

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of its workability and durability (RMRDC 1998). Wood iscommonly harvested by the clear-cutting method, a processwherein all vegetation within a given area is removed forprocessing. Now, where clear-cutting takes place, lumbercompanies are obliged to replant the area. However,replanting alone does not replace the natural biologicaldiversity that existed before harvesting since same-species plantings are particularly vulnerable to diseaseand insects. “Selective cutting”, is however beenpracticed today by most lumber companies. Choosing onlythose trees large enough or valuable enough to remove andleaving the surrounding vegetation intact. In line withthe above, Sustainable forestry is now in practice, inwhich timber growth equals or exceeds harvesting rates inboth quantity and quality.

BAMBOO: - bamboo like stone is known to be one of theoldest materials used in building construction works. Itis a giant grass of about 1250 species worldwide (sharman,1980). It grows from tropical to sub-temperate regions andis known to be one of the fastest growing plants in theworld, with its growth rate ranging from 30cm to 100cm perday. Bamboo grows densely and can be easily regeneratednaturally. It attains its maximum size in 60-90 days ofshoot sprouting and can be harvested in 3-6 yearsdepending upon species. Its natural expansion ability,strength, flexibility, versatility and availability havemade it well known as an environmentally green plant(Zehui, 2007).

Selecting Sustainable Building Materials

CriteriaThe reason for selecting certain building materials forconstruction works in a given region from ancient times has often

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been influenced by the availability of such material, itsconstruction technique and availability of skilled labour, thestrength and durability of such a material. This is demonstratedby the use of materials such as stones and mud by ancientEgyptians and the Romans. Green architecture on its part covers awider scope of environmental issues: raw material extraction andharvesting, manufacturing processes, construction techniques, anddisposal of demolition waste, in considering materials fit to becalled sustainable building materials, hence qualified for use inconstructing green buildings. The criteria for selectingsustainable building materials shall however be broken down intothree basic stages as shown below.

1. MANUFACTURING PROCESS (Pre-Building Phase): - under themanufacturing process of a material, the under listed wouldbe considered:

- Waste reduction- Pollution prevention- Recyclability- Embodied energy reduction- Natural materials and- Availability2. BUILDING OPERATION (Building Phase): -- Energy efficiency- Water treatment and conservation- Nontoxic substances- Renewable energy source- Longer life.3. WASTE MANAGEMENT (Post Building Phase): -- Biodegradable- Recyclability- Reusable- Others 1). MANUFACTURING PROCESS (Pre-Building Phase):

The Pre-Building Phase describes the production and deliveryprocess of a material excluding the installation. This includesdiscovering raw materials in nature as well as extracting,

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manufacturing, parceling, and delivering on site. This phase isthe most prone to causing environmental damage. A fore knowledgeof the environmental impact in this phase will help in the properselection of building materials to be used since Raw materialprocurement methods (majorly by mining and clear cutting), themanufacturing process itself, and the distance from themanufacturing location to the building site all haveenvironmental consequences.

- Waste ReductionFor waste to be checked during manufacturing, production process has to be made more efficient, by reducing the amount of scrap material that results from the various molding, trimming, and finishing processes, or from defective and damaged products. Suchmaterials can be reincorporated into the product or removed for recycling elsewhere. These greatly reduce the amount of waste that goes into landfills.

- Use of Natural MaterialsNatural materials are generally lower in embodied energy and toxicitythan man-made materials. They require less processing and areless damaging to the environment. Many like bamboos, wood, aretheoretically renewable. When natural materials are incorporatedinto building products, the products become more sustainable. - Pollution prevention: - it is obvious that lots ofmanufacturers neither care about where their raw materials comefrom, how there are gathered, how it affects their health in thecause of production and it’s effects on users and above all howthese materials affect the eco-system. Identical buildingmaterials may be produced by several manufacturers using variousprocesses. Though all bound by government regulations onpollution, some individuals companies go far beyond legalrequirements in ensuring their process pollute as little aspossible. For example water is a major element in the productionof building materials like cement, steel, linoleum dye, e.t.c,the waste water could be easily released to water bodies around,

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thereby making it unfit for consumption and inhabitable for seaanimals. - Recycled content: - the idea behind recycling ofmaterials is majorly meant to reduce material waste and thedemand on virgin natural resources. Recycling of materials savesand preserves the embodied energy there in, and the energy usedin recycling is far less than that needed for the originalmanufacturing. For example: aluminum can be recycled for 10%-20%of the energy required to transform raw ore into a finished good.

KEY BUILDING MATERIALS WITH POTENTIAL FOR RECYCLINGGlassPlasticMetalConcreteBrickWood

- Embodied energy: - the embodied energy of a materialrefers to the total energy required to produce that material,including the collection of raw materials, fuel used to power theharvesting or mining equipments, the processing equipment, andtransportation to processing facility. The greater a material’sembodied energy, the greater the amount of energy required toproduce it, implying more severe ecological consequences. Forinstance, the processing of mud brick or wood involves far lessenergy and releases less pollution than the processing of steel.

- Availability: -Using locally produced building materials shortenstransportation distances, thus reducing air pollution produced byvehicles. Often, local materials are better suited to climaticconditions, and these support area economies. It is not alwayspossible to use locally available materials, but if materials must beimported they should be used selectively and in as small a volume aspossible. For instance, the decorative use of marble quarried halfwayaround the world is not a sustainable choice. Steel on the other hand,when required for structural strength and durability, is a justifiableuse of a material that is generally manufactured some distance fromthe building site.

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2). BUILDING OPERATION (Building Phase): -The building phase refers to the useful life of a material andbegins at the point of assemblage into a structure, maintenanceand repair, and runs through the life of the material within oras part of the building. Since protection of the indoorenvironment does not stop on completion of the construction, airquality must be ensured through the use of renewed energysystems, use of non toxic materials, energy efficient materialsand by a routinely scheduled maintenance and housekeeping.

- Energy efficiency: - for a building material to be consideredas green, considerations most be given to the amount ofenergy the material shields from the building. it isinteresting to note that the long-term energy costs ofoperating a building are heavily dependent on the materialsused in its construction. However materials with highinsulating value(R- value) are better insulators. The amountof heat gain from direct sunlight can also be minimized bythe use of various shading devices, glass types and glazingpatterns.

- Water treatment and conservation: - this factor addresses theefficient use of water on a building site, and encompassesincrease in quality of water and reduction in amount ofwater used. Reducing the amount of consumption can beattained in two ways: (1) by physically restricting thevolume of water that can pass through a fixture (faucet,toilet, and showerhead), or (2) by the recycling of waterthat has already entered the site. For instance, channelingwaste water from wash hand basins and kitchen sinks to flushtoilets; rainwater may be used for bathing, washing and evenfor irrigation purposes. Green architecture, also advocatesthat all water coming into or leaving a building must betreated.

- Use of less-toxic materials: - toxic materials as the nameimplies, contains and emits toxins which are harmful tohuman life. Many materials adversely affect indoor air

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quality and expose occupants to health hazards. Forinstance, some adhesives and paints, the resins in plywood,particleboard, and the chemicals used in foam insulationhave been implicated in sick building syndrome. The problemof indoor air contamination is magnified by the increasingair tightness of buildings. Hence reduced air infiltrationand increase occupants exposure to higher concentration oftoxins for longer periods. Higher air cycling rates arerecommended during installation of materials containingpetroleum distillates known as volatile organic compounds(VOCs).

- Renewable energy: - the earth from time immemorial hasbenefited from solar energy as the major source of energyincome. Today building sites are surrounded by naturalenergy in the form of wind, solar radiation, geothermalheat, biomass from waste materials, ethanol from cropresidues, photovoltaic, tidal and hydro energy. Renewableenergy systems can be used to supplement or eliminatetraditional heating, cooling and electrical systems throughthe utilization of this natural energy. In many parts of thecountry, solar, wind and hydro energy can be adopted assources of power generation and supply. A building that ismore than a quarter mile from a power line, it may be lessexpensive to provide “off grid” than to connect to a grid.

- Longer life: - the durability of a material determines to alarge extent its cost effectiveness and only needs to bereplaced less often. This reduces the amount of rawmaterials needed for its manufacturing and money spent oninstallation and labour cost. It will also produce lesswaste for landfills. Most durable building materials alsohave considerably low maintenance cost.

3). WASTE MANAGEMENT/DISPOSAL ( Post Building Phase): -The post building phase refers to the building materials whentheir usefulness in a building has expired. At this point, amaterial may be reused in its entirety, partly or discarded

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completely. Designers are scarcely concerned with this phase,yet the demolition of buildings and disposal of the resultingwaste causes a high environmental threat. Degradable materialsmay produce toxic waste and inert materials consume landfillspace, the adaptive use of existing structures, conserve theenergy that went into its materials and construction

- Biodegradability: - this refers to its potential to naturallydecompose when disposed off. Not many materials used inconstruction today can return to the earth rapidly whendiscarded, i.e like steel, glass, polyethene e.t.c.thereby causing lots of troubles to the eco-systemincluding landfills, sewage blockage, erosion e.t.c.therefore, a major factor to be considered in selectinga green material, is the ability for that material torot by chemicals or biological decomposition whendiscarded. Example, timber, adobe, straw, tharch, anothers.

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GOING GREEN AND STAYING GREEN

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