sustainable architecture module: introduction to sustainable design

Introduction to Sustainable Design December 1998 Sustainable Design • 1

Sustainable Architecture Module:

Introduction toSustainable Design

Written byJong-Jin Kim, Assistant Professor of Architecture,and Brenda Rigdon, Project Intern

College of Architecture and Urban PlanningThe University of Michigan

Published byNational Pollution Prevention Center for Higher Education,430 E. University Ave., Ann Arbor, MI 48109-1115734.764.1412 • fax: 734.647.5841 • [email protected]: www.umich.edu/~nppcpub/

This compendium was made possible in part by a grant from the 3M

Corporation. These materials may be freely copied for educational purposes.

2 • Sustainable Design December 1998 Introduction to Sustainable Design


ContentsList of Figures ............................................................................. 5

Fundamentals

Changing our Definitions of Growth and Progress.................5

Resource Consumption and Environmental Pollution............5

Sustainability in Architecture.................................................. 6

Principles of Sustainable Design

Principle 1: Economy of Resources....................................... 9

Principle 2: Life Cycle Design .............................................. 11

Principle 3: Humane Design ................................................ 14

Summary .............................................................................. 15

Methods for Achieving Sustainable Design

Economy of Resources........................................................ 16

Energy Conservation.................................................. 16

Water Conservation.................................................... 20

Materials Conservation .............................................. 21

Life Cycle Design ................................................................. 22

Pre-Building Phase..................................................... 22

Building Phase............................................................ 24

Post-Building Phase ................................................... 25

Humane Design.................................................................... 27

Preservation fo Natural Conditions ............................ 27

Urban Design and Site Planning................................ 27

Design for Human Comfort ........................................ 28

Sustainable Design Bibliography......................... 29

Sustainable Design Annotated Bibliography ......33


List of Figures

Figure 1 Income vs. energy consumption............................6

Figure 2 Income vs. water consumption..............................6

Figure 3. Income vs. pollutant production ............................6

Figure 4 Framework for sustainable architecture................8

Figure 5 Material-flow diagram ........................................... 9

Figure 6 Conventional model of the building life cycle......11

Figure 7 Sustainable building life cycle ............................ 11

Figure 8 Ecological elements of site and building .............13

Figure 9 Methods for “Economy of Resources”.................17

Figure 10 Methods for “Life Cycle Design” ..........................23

Figure 11 Methods for “Humane Design” ........................... 26


Fundamentals

Changing our Definitions of Growth and Progress

How do we measure economic success? Traditionally, wemeasure Gross National Product (GNP), which favors anyeconomic activities and production, regardless of their truebenefits and effect on long-term societal well-being. Evenconsumption, demolition, and waste that require furtherproduction are credited to a higher GNP. In industrialized,capitalistic societies, consumption is regarded as a virtue.

However, realizing the environmental threats, real or potential,to the quality of life, environmental movements have begunin virtually all sectors of industrialized countries, includingbusiness, manufacturing, transportation, agriculture, andarchitecture. Researchers are developing and refiningmethods of analyzing the true cost of an economic activityover its entire life cycle.

Developing countries tend to model their economic infra-structure after those of their industrialized counterparts.Today, economic activities in developing countries aroundthe world, Pacific Rim countries in particular, are far morenoticeable than two or three decades ago, and their share ofthe world economy is increasing. All quantitative economicindices such as per capita income, GNP, amount of foreigntrade, and the amount of building construction indicate thattheir economies are strong and growing rapidly.

Measuring a country’s GNP does not account for the loss ofenvironmental quality — and quality of life — attributed toindustrialization. In the United States alone, billions of dollarshave been spent cleaning up an environment subjected touncontrolled development. The ecological havoc created bythe former Soviet Union is only now beginning to be fullyunderstood. Developing countries would do well to learnfrom these situations, not emulate them.

Resource Consumption and Environmental Pollution

Resource consumption and economic status have a strongcorrelation. As the income level of a society increases, so doesits resource consumption. This is true for societies of virtuallyany size, be they families, cities, or entire countries.


The correlation between per-capita income and energyconsumption of various countries demonstrates this trend. Asshown in Figure 1, industrial countries with higher incomesconsume more energy per capita than developing countries.Among industrialized countries, the energy intensity ofCanada and the United States is the highest, while Japan’s ismuch lower. This implies that it is plausible for a society toestablish resource-efficient social and economic infrastructureswhile raising its economic status. A society (household, com-munity, city, or country) with such an infrastructure will beless susceptible to resource shortages, more reliable by itself,and thus more sustainable in the future.

The correlation between per-capita income and per-capitawater consumption reveals a similar pattern (see Figure 2),as does the emission of environmental pollutants to theatmosphere (see Figure 3). Developing countries’ energyuse, water use, and share of global environmental pollutionis expected to increase.

Sustainability in Architecture

The World Commission on Environment and Developmenthas put forth a definition of “sustainability” as

meeting the needs of the present withoutcompromising the ability of future generationsto meet their own needs.

— From Our Common Future

(London: Oxford University Press, 1987).

This definition of sustainability does not specify the ethicalroles of humans for their everlasting existence on the planet.It also fails to embrace the value of all other constituentsparticipating in the global ecosystem. The need for findinglong-terms solutions that warrant continuing human existenceand well-being is far more compelling than that of findinga proper terminology to describe the human need. In thisrespect, the debate on the terms “green,” “sustainable,” or“ecological” architecture is not terribly important.

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Figure 1: Correlations betweenper-capita incomes and per-capita energy consumptionlevels of selected industrializedand developing countries. [Source:Herman Daly, Steady-State Economics

(Washington: Island Press, 1991).]

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Figure 2: Correlations betweenper-capita incomes and per-capitawater consumptions of selectedindustrialized and developingcountries. [Source: Herman Daly,Steady-State Economics (Washington:Island Press, 1991).]

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Figure 3: Correlations betweenper-capita incomes and per-capitapollutant production of selectedindustrialized and developingcountries. [Source: Herman Daly,Steady-State Economics (Washington:Island Press, 1991).]

Architecture is one of the most conspicuous forms of economicactivity. It is predicted that the pattern of architectural resourceintensity (the ratio of per-capita architectural resourceconsumption to per-capita income) will generally follow thesame patterns as shown in Figure 1, 2, and 3. A country’seconomic development will necessitate more factories, officebuildings, and residential buildings. For a household, thegrowth of incomes will lead to a desire for a larger housewith more expensive building materials, furnishings andhome appliances; more comfortable thermal conditions ininterior spaces; and a larger garden or yard.

During a building’s existence, it affects the local and globalenvironments via a series of interconnected human activitiesand natural processes. At the early stage, site development andconstruction influence indigenous ecological characteristics.Though temporary, the influx of construction equipment andpersonnel onto a building site and process of constructionitself disrupt the local ecology. The procurement and manu-facturing of materials impact the global environment. Oncebuilt, building operation inflicts long-lasting impact on theenvironment. For instance, the energy and water used by itsinhabitants produce toxic gases and sewage; the process ofextracting, refining, and transporting all the resources usedin building operation and maintenance also have numerouseffects on the environment.

Architectural professionals have to accept the fact that as asociety’s economic status improves, its demand for architecturalresources — land, buildings or building products, energy,and other resources — will increase. This in turn increasesthe combined impact of architecture on the global ecosystem,which is made up of inorganic elements, living organisms,and humans. The goal of sustainable design is to findarchitectural solutions that guarantee the well-being andcoexistence of these three constituent groups.


Principles of Sustainable Design

To educate architects to meet this goal of coexistence, we havedeveloped a conceptual framework. The three levels of theframework (Principles, Strategies, and Methods) correspond tothe three objectives of architectural environmental education:creating environmental awareness, explaining the buildingecosystem, and teaching how to design sustainable buildings.The overall conceptual diagram for sustainable design isshown in Figure 4.

We propose three principles of sustainability in architecture.Economy of Resources is concerned with the reduction, reuse,and recycling of the natural resources that are input to abuilding. Life Cycle Design provides a methodology foranalyzing the building process and its impact on the environ-ment. Humane Design focuses on the interactions betweenhumans and the natural world. These principles can providea broad awareness of the environmental impact, both localand global, of architectural consumption.

Figure 4: Conceptual frameworkfor Sustainable Design andPollution Prevention inArchitecture.

SUSTAINABLE DESIGN AND POLLUTION PREVENTION

Principles

Economy of Life Cycle HumaneResources Design Design

Strategies

Energy Pre-Building PreservationConservation Phase of Natural

Conditions

Water Building Urban DesignConservation Phase Site Planning

Material Post-Building Design forConservation Phase Human Comfort

Methods


Building

Building Materials

Consumer Goods

Figure 5: The input and outputstreams of resource flow.

Principle 1: Economy of Resources

By economizing resources, the architect reduces the use ofnonrenewable resources in the construction and operation ofbuildings. There is a continuous flow of resources, naturaland manufactured, in and out of a building. This flow beginswith the production of building materials and continuesthroughout the building’s life span to create an environment forsustaining human well-being and activities. After a building’suseful life, it should turn into components for other buildings.

When examining a building, consider two streams of resourceflow (see Figure 5). Upstream, resources flow into the buildingas input to the building ecosystem. Downstream, resourcesflow out of the building as output from the building ecosystem.In a long run, any resources entered into a building ecosystemwill eventually come out from it. This is the law of resourceflow conservation.

For a given resource, its forms before entry to a building andafter exit will be different. This transformation from input tooutput is caused by the many mechanical processes or humaninterventions rendered to the resources during their use inbuildings. The input elements for the building ecosystem are

Each of these principles embody a unique set of strategies.Studying these strategies leads students to more thoroughunderstanding of architecture’s interaction with the greaterenvironment. This allows them to further disaggregate andanalyze specific methods architects can apply to reduce theenvironmental impact of the buildings they design.

MATERIAL FLOW IN THE BUILDING ECOSYSTEM

Upstream Building Downstream

Building Materials Used Materials

Energy Combustion Byproducts

Water Graywater Sewage

Consumet Goods Recycleable Materials

Solar Radiation Wasted Head

Wind Polluted Air

Rain Groundwater


diverse, with various forms, volumes, and environmentalimplications.

The three strategies for the economy of resources principle areenergy conservation, water conservation, and material conservation.Each focuses on a particular resource necessary for buildingconstruction and operation.

Energy ConservationAfter construction, a building requires a constant flow of energyinput during its operation. The environmental impacts ofenergy consumption by buildings occur primarily away fromthe building site, through mining or harvesting energy sourcesand generating power. The energy consumed by a buildingin the process of heating, cooling, lighting, and equipmentoperation cannot be recovered.

The type, location, and magnitude of environmental impactsof energy consumptions in buildings differ depending on thetype of energy delivered. Coal-fired electric power plantsemit polluting gases such as SO

2 , CO

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x into the

atmosphere. Nuclear power plants produce radioactivewastes, for which there is currently no permanent managementsolution. Hydropower plants each require a dam and areservoir which can hold a large body of water; constructionof dams results in discontinuance of river ecosystems and theloss of habitats for animals and plants.

Water ConservationA building requires a large quantity of water for the purposesof drinking, cooking, washing and cleaning, flushing toilets,irrigating plants, etc.. All of this water requires treatmentsand delivery, which consume energy. The water that exitsthe building as sewage must also be treated.

Material ConservationA range of building materials are brought onto building sites.The influx of building materials occurs primarily during theconstruction stage. The waste generated by the constructionand installation process is significant. After construction,a low-level flow of materials continues in for maintenance,replacement, and renovation activities. Consumer goodsflow into the building to support human activities. All ofthese materials are eventually output, either to be recycledor dumped in a landfill.


Principle 2: Life Cycle Design

The conventional model of the building life cycle is a linearprocess consisting of four major phases: design; construction;operation and maintenance; and demolition (see Figure 6).The problem with this model is that it is too narrowly defined:it does not address environmental issues (related to the pro-curement and manufacturing of building materials) or wastemanagement (reuse and recycling of architectural resources).

The second principle of sustainable architecture is life cycledesign (LCD). This “cradle-to-grave” approach recognizesenvironmental consequences of the entire life cycle of architec-tural resources, from procurement to return to nature. LCD isbased on the notion that a material transmigrates from oneform of useful life to another, with no end to its usefulness.

For the purpose of conceptual clarity, the life cycle of a buildingcan be categorized into three phases: pre-building, building, andpost-building, as shown in Figure 7. These phases are connected,and the boundaries between them are not obvious. The phasescan be developed into LCD strategies that focus on minimizingthe environmental impact of a building. Analyzing the buildingprocesses in each of these three phases provides a better under-standing of how a building’s design, construction, operation,and disposal affect the larger ecosystem.

ConstructionDesign Operation &Maintenance

Demolition➞ ➞➞

Figure 6: Conventional model ofthe building life cycle.

Construction

Operation andMaintenance

Building Phase

Post-Building Phase

Pre-Building Phase

Extraction

Processing

Manufacturing

Transportation

Nature

WasteManagement

Reuse

Recycle

Figure 7: The sustainable buildinglife cycle.


Pre-Building PhaseThis phase includes site selection, building design, and buildingmaterial processes, up to but not including installation. Underthe sustainable-design strategy, we examine the environmentalconsequences of the structure’s design, orientation, impact onthe landscape, and materials used.

The procurement of building materials impacts the environ-ment: harvesting trees could result in deforestation; miningmineral resources (iron for steel; bauxite for aluminum; sand,gravel, and limestone for concrete) disturbs the natural envi-ronment; even the transport of these materials can be a highlypolluting activity, depending on their weight and distancefrom the site. The manufacturing of building products alsorequires energy and creates environmental pollution: forexample, a high level of energy is required to manufacturesteel or aluminum products.

Building PhaseThis phase refers to the stage of a building’s life cycle when abuilding is physically being constructed and operated. In thesustainable-design strategy, we examine the construction andoperation processes for ways to reduce the environmentalimpact of resource consumption; we also consider long-termhealth effects of the building environment on its occupants.

Post-Building PhaseThis phase begins when the useful life of a building has ended.In this stage, building materials become resources for otherbuildings or waste to be returned to nature. The sustainable-design strategy focuses on reducing construction waste (whichcurrently comprises 60% of the solid waste in landfills1) byrecycling and reusing buildings and building materials.

For more information on this topic, see Recycling and Reuseof Building Materials. This “Sustainable Architecture” moduleis available for a small fee from the Center for SustainableSystems (formerly the NPPC; see the front page of this documentfor contact information) or free of charge on our website:www.umich.edu/~nppcpub/resources/compendia/architecture.html

1 Sim Van der Ryn and Peter Calthorpe, Sustainable Communities(San Francisco: Sierra Club Books, 1986).


Site and Building InteractionsThe LCD concept calls for consideration of the environmentalconsequences of buildings in all three phases of the life cycle.Each phase of building life cycle is associated with two groupsof ecological elements: site and building (see Figure 8). Theprincipal domain of architectural design is in the buildingphase, but sustainable building can be achieved by findingways to minimize environmental impacts during all threephases of building life cycle.

Figure 8: Ecological elements ofSite and Building associated withthe building life-cycle phases.

SITE: Elements of site ecology BUILDING: Natural orthat exist within or in the vicinity manufactured resources,of a building site, including sun- such as building materials,light, wind, precipitation, water water, or energy ...table, soil, flora, fauna, etc. ...

... before construction. ... before they arrive at the site.

... from the time construction ... from the time they arrivebegins through the duration of at the site for installation orthe building’s useful life. operation though the duration

of the building’s useful life.

... after the building’s useful life. ... after the building’s useful life.


Principle 3: Humane Design

Humane design is the third, and perhaps the most important,principle of sustainable design. While economy of resourcesand life cycle design deal with efficiency and conservation,humane design is concerned with the livability of all constitu-ents of the global ecosystem, including plants and wildlife.This principle arises from the humanitarian and altruistic goalof respecting the life and dignity of fellow living organisms.Further examination reveals that this principle is deeplyrooted in the need to preserve the chain elements of theecosystems that allow human survival.

In modern society, more than 70% of a person’s lifespan is spentindoors. An essential role of architecture is to provide builtenvironments that sustain occupants’ safety, health, physio-logical comfort, psychological well-being, and productivity.

Because environmental quality is intangible, its importancehas often been overlooked in the quest for energy and envi-ronmental conservation, which sometimes seemed to mean“shivering in the dark.” Compounding the problem, manybuilding designers have been preoccupied with style andform-making, not seriously considering environmentalquality in and around their built environments .

Remember the performance factor of design. When a productsaves energy, does it perform as well as what it is replacing?And how does it affect the performance of building occupants?For instance, early fluorescent lighting systems were moreefficient than their incandescent counterparts; however, somefluorescents were known to buzz. The bulb might save $30in annual energy costs, but if the noise irritated the employeeworking nearby, the employee’s resulting drop in productivitycould cost the employer a lot more, thereby wiping out anyfinancial benefits gained from lighting energy conservation.

A general rule of thumb in such comparisons is that the annualenergy bill of a typical office building amounts to around fivehours of employee labor cost; therefore, any building energyconservation strategy that annually reduces productivity bymore than five hours per employee defeats its purpose. Thisis not to say that energy conservation can’t be financiallybeneficial, just that it should be kept in holistic perspective,taking other pertinent factors into account.


The following three strategies for humane design focus onenhancing the coexistence between buildings and the greaterenvironment, and between buildings and their occupants,

Preservation of Natural ConditionsAn architect should minimize the impact of a building on itslocal ecosystem (e.g., existing topography, plants, wildlife).

Urban Design and Site PlanningNeighborhoods, cities, and entire geographic regions canbenefit from cooperative planning to reduce energy andwater demands. The result can be a more pleasant urbanenvironment, free of pollution and welcoming to nature.

Human ComfortAs discussed previously, sustainable design need notpreclude human comfort. Design should enhance the workand home environments. This can improve productivity,reduce stress, and positively affect health and well-being.

Summary

To achieve environmental sustainability in the building sec-tor, architects must be educated about environmental issuesduring their professional training. Faculty have to fosterenvironmental awareness, introduce students to environmentalethics, and developing their skills and knowledge-base insustainable design.

The current status of sustainable design in architecture is thatof an ethic rather than a science. While a change of lifestylesand attitudes toward the local and global environments isimportant, the development of scientific knowledge-basesthat provide skills, techniques, and methods of implementingspecific environmental design goals is urgent.

To enhance environmental sustainability, a building mustholistically balance and integrate all three principles —Sustainable Design, Economy of Resources, and Life CycleDesign — in design, construction, operation and maintenance,and recycling and reuse of architectural resources. Theseprinciples comprise a conceptual framework for sustainablearchitectural design. This framework is intended to helpdesigners seek solutions rather than giving them a set ofsolutions. Specific design solutions compatible with a givendesign problem will emanate from these principles.


Methods for Achieving Sustainable Design

The ultimate goal and challenge of sustainable design is tofind win-win solutions that provide quantitative, qualitative,physical, and psychological benefits to building users. Thereare many possibilities for achieving this seemingly difficultgoal. The three principles of sustainable design — economyof resources, life cycle design, and humane design — providea broad awareness of the environment issues associated witharchitecture. The strategies within each principle focus onmore specific topics. These strategies are intended to fosteran understanding of how a building interacts with the internal,local, and global environments. This section discusses methodsfor applying sustainable design to architecture.

Economy of Resources

Conserving energy, water, and materials can yield specificdesign methods that will improve the sustainability of archi-tecture (see Figure 8). These methods can be classified astwo types.

1) Input-reduction methods reduce the flow of nonrenewableresources input to buildings. A building’s resourcedemands are directly related its efficiency in utilizingresources.

2) Output-management methods reduce environmentalpollution by requiring a low level of waste and properwaste management.

Energy ConservationEnergy conservation is an input-reduction method. The maingoal is to reduce consumption of fossil fuels. Buildings con-sume energy not only in their operation, for heating, lightingand cooling, but also in their construction. The materialsused in architecture must be harvested, processed, and trans-ported to the building site. Construction itself often requireslarge amounts of energy for processes ranging from movingearth to welding.

Energy-Conscious Urban Planning

Cities and neighborhoods that are energy-conscious are notplanned around the automobile, but around public transpor-tation and pedestrian walkways. These cities have zoninglaws favorable to mixed-use developments, allowing people


to live near their workplaces. Urban sprawl is avoided byencouraging redevelopment of existing sites and the adaptivereuse of old buildings. Climatic conditions determine orienta-tion and clustering. For example, a very cold or very hot anddry climate might require buildings sharing walls to reduceexposed surface area; a hot, humid climate would requirewidely spaced structures to maximize natural ventilation.

Figure 9: “Economy of Resources”methods of application.


Principle 1:

Economy of Resources

Strategies

Energy Water MaterialConservation Conservation Conservation

Methods

Reduction:

- Indigenouslandscaping

- Low-flowshowerheads

- Vacuum-assisttoilets or smallertoilet tanks

Reuse:

- Rainwatercollection

- Graywatercollection

Material-conservingdesign andconstruction

Proper sizing ofbuilding systems

Rehabilitation ofexisting structures

Use of reclaimedor recycledmaterials andcomponents

Use of non-conventionalbuilding materials

Energy-consciousurban planning

Energy-conscioussite planning

Alternativesources of energy

Passive heatingand cooling

Avoidance of heatgain or heat loss

Use of low-embodied-energymaterials

Use of energy-efficientappliances withtiming devices


Energy-Conscious Site Planning

Such planning allows the designer to maximize the use ofnatural resources on the site. In temperate climates, opensouthern exposure will encourage passive solar heating;deciduous trees provide shade in summer and solar heat gainin winter. Evergreens planted on the north of a building willprotect it from winter winds, improving its energy efficiency.Buildings can be located relative to water onsite to providenatural cooling in summer.

Passive Heating and Cooling

Solar radiation incident on building surfaces is the most sig-nificant energy input to buildings. It provides heat, light, andultraviolet radiation necessary for photosynthesis. Historically,architects have devised building forms that provide shadingin summer and retain heat in winter. This basic requirementis often overlooked in modern building design. Passive solararchitecture offers design schemes to control the flow of solarradiation using building structure, so that it may be utilizedat a more desirable time of day.

Shading in summer, by plants or overhangs, prevents summerheat gain and the accompanying costs of air-conditioning.The wind, or the flow of air, provides two major benefits:cooling and hygienic effects. Prevailing winds have longbeen a major factor in urban design. For instance, proposalsfor Roman city layouts were primarily based on the directionof prevailing winds.

Insulation

High-performance windows and wall insulation preventboth heat gain and loss. Reducing such heat transfer reducesthe building’s heating and cooling loads and thus its energyconsumption. Reduced heating and cooling loads requiresmaller HVAC equipment, and the initial investment needfor the equipment will be smaller.

Aside from these tangible benefits, high-performance windowsand wall insulation create more comfortable thermal environ-ments. Due to the insulating properties of the materials, thesurface temperatures of windows and walls will be higher inthe winter and lower in the summer. The installation ofsmaller HVAC equipment reduces mechanical noise andincreases sonic quality of the indoor space.


Alternate Sources of Energy

Solar, wind, water, and geothermal energy systems are allcommercially available to reduce or eliminate the need forexternal energy sources. Electrical and heating requirementscan be met by these systems, or combination of systems, in allclimates.

Daylighting

Building and window design that utilizes natural light willlead to conserving electrical lighting energy, shaving peakelectric loads, and reducing cooling energy consumptions.At the same time, daylighting increases the luminous qualityof indoor environments, enhancing the psychological well-being and productivity of indoor occupants. These qualitativebenefits of daylighting can be far more significant than itsenergy-savings potential.

Energy-Efficient Equipment & Appliances

After construction costs, a building’s greatest expense is thecost of operation. Operation costs can even exceed constructioncosts over a building’s lifetime. Careful selection of high-efficiency heating, cooling, and ventilation systems becomescritical. The initial price of this equipment may be higherthan that of less efficient equipment, but this will be offsetby future savings.

Appliances, from refrigerators to computers, not only consumeenergy, they also give off heat as a result of the inefficient useof electricity. More efficient appliances reduce the costs ofelectricity and air-conditioning. The U. S. EnvironmentalProtection Agency has developed the “Energy Star” programto assist consumers in identifying energy efficient electronicequipment.

Choose Materials with Low Embodied Energy

Building materials vary with respect to how much energy isneeded to produce them. The embodied energy of a materialattempts to measure the energy that goes into the entire lifecycle of building material. For instance, aluminium has avery high embodied energy because of the large amount ofelectricity that must be used to manufacture it from minedbauxite ore; recycled aluminum requires far less energy torefabricate. By choosing materials with low embodied energy,the overall environmental impact of a building is reduced.Using local materials over imported materials of the sametype will save transportation energy.


Water ConservationMethods for water conservation may reduce input, output, orboth. This is because, conventionally, the water that is suppliedto a building and the water that leaves the building as sewageis all treated by municipal water treatment plants. Therefore,a reduction in use also produces a reduction in waste.

Reuse Water Onsite

Water consumed in buildings can be classified as two types:graywater and sewage. Graywater is produced by activitiessuch as handwashing. While it is not of drinking-water quality,it does not need to be treated as nearly as intensively as sewage.In fact, it can be recycled within a building, perhaps to irrigateornamental plants or flush toilets. Well-planned plumbingsystems facilitate such reuse.

In most parts of the world, rainwater falling on buildings hasnot been considered a useful resource. Buildings are typicallydesigned to keep the rain from the occupants, and the idea ofutilizing rain water falling on building surfaces has not beenwidely explored. Building envelopes, particularly roofs, canbecome rainwater collecting devices, in combination withcisterns to hold collected water. This water can be used forirrigation or toilet-flushing.

Reduce Consumption

Water supply systems and fixtures can be selected to reduceconsumption and waste. Low-flow faucets and small toilettanks are now required by code in many areas of the country.Vacuum-assisted and biocomposting toilets further reducewater consumption. Biocomposting toilets, available on bothresidential and commercial scales, treat sewage on site, elimi-nating the need for energy-intensive municipal treatment.

Indigenous landscaping — using plants native to the localecosystem — will also reduce water consumption. Theseplants will have adapted to the local rainfall levels, eliminatingthe need for additional watering. Where watering is needed,the sprinkler heads should be carefully placed and adjustedto avoid watering the sidewalk and street.


Materials ConservationThe production and consumption of building materials hasdiverse implications on the local and global environments.Extraction, processing, manufacturing, and transportingbuilding materials all cause ecological damage to some extent.There are input and output reduction methods for materialsconservation. As with water, some of these methods overlap.

Adapt Existing Buildings to New Uses

One of the most straightforward and effective methods formaterial conservation is to make use of the resources thatalready exist in the form of buildings. Most buildings outlivethe purpose for which they were designed. Many, if not all,of these buildings can be converted to new uses at a lowercost than brand-new construction.

Incorporate Reclaimed or Recycled Materials

Buildings that have to be demolished should become theresources for new buildings. Many building materials, suchas wood, steel, and glass, are easily recycled into new materials.Some, like brick or windows, can be used whole in the newstructure. Furnishing, particularly office partition systems,are also easily moved from one location to another.

Use Materials That Can Be Recycled

During the process of designing the building and selectingthe building materials, look for ways to use materials that canthemselves be recycled. This preserves the energy embodiedin their manufacture.

Size Buildings and Systems Properly

A building that is oversized for its designed purpose, or hasoversized systems, will excessively consume materials. Whena building is too large or small for the number of people itmust contain, its heating, cooling, and ventilation systems,typically sized by square footage, will be inadequate or ineffi-cient. This method relates directly to the programming anddesign phases of the architectural process. The client’s presentand future space needs must be carefully studied to ensurethat the resulting building and systems are sized correctly.

Architects are encouraged to design around standardizedbuilding material sizes as much as possible. In the U. S., thisstandard is based on a 4'x8' sheet of plywood. Excess trimmingof materials to fit non-modular spaces generates more waste.


Reuse Non-Conventional Products as Building Materials

Building materials from unconventional sources, such asrecycled tires, pop bottles, and agricultural waste, are readilyavailable. These products reduce the need for new landfillsand have a lower embodied energy that the conventionalmaterials they are designed to replace.

Consumer Goods

All consumer goods eventually lose their original usefulness.The “useful life” quantifies the time of conversion from theuseful stage to the loss of original usefulness stage. For in-stance, a daily newspaper is useful only for one day, a phonebook is useful for one year, and a dictionary might be usefulfor 10 years. The shorter the useful life of consumer goods,the greater the volume of useless goods will result. Conse-quently, more architectural considerations will be requiredfor the recycling of short-life consumer goods.

The conventional term for consumer goods that have losttheir original usefulness is waste. But waste is or can be aresource for another use. Therefore, in lieu of waste, it isbetter to use the term “recyclable materials.” One waybuildings can encourage recycling is to incorporate facilitiessuch as on-site sorting bins.

Life Cycle Design

As discussed earlier, the Life Cycle Design principle embodiesthree strategies: pre-building, building, and post-building.These strategies, in turn, can yield specific design methodsthat will improve the sustainability of architecture. Figure 10shows how each method relates to the main strategies of LifeCycle Design. These methods focus mainly on reducing in-put. Consuming fewer materials lessens the environmentalimpact of the associated manufacturing processes. This thenreduces the eventual output of the building ecosystem.

Pre-Building PhaseDuring the Pre-Building Phase, the design of a building andmaterials selected for it are examined for their environmentalimpact. The selection of materials is particularly important atthis stage: the impact of materials processing can be globaland have long-term consequences.


Use Materials Made From Renewable Resources

Renewable resources are those that can be grown or harvestedat a rate that exceeds the rate of human consumption. Usingthese materials is, by definition, sustainable. Materials madefrom nonrenewable materials (petroleum, metals, etc.) are,ultimately, not sustainable, even if current supplies areadequate. Using renewable materials wherever possiblereduces the need for nonrenewable materials.

Figure 10: “Life Cycle Design”methods of application.


Principle 2:

Life Cycle Design

Strategies

Pre-Building Building Post-Building

Methods

Use materials thatare ...

- made of renew-able resources

- harvested orextracted with-out ecologicaldamage

- recycled

- recyclable

- long-lasting andlow maintenance

Minimize energyneeded to distrib-ute materials.

Schedule con-struction tominimize siteimpact.

Provide waste-separationfacilities.

Use nontoxicmaterials toprotect construc-tion workers aswell as end users.

Specify regularmaintenance withnontoxic cleaners.

Adapt existingstructures tonew users andprograms.

Reuse buildingcomponents andmaterials.

Recycle buildingcomponents andmaterials.

Reuse the landand existinginfrastructure.


Use Materials Harvested or Extracted Without Causing Ecological Damage

Of the renewable materials available, not all can be obtainedwithout significant environmental effects. Therefore, thearchitect must be aware of how various raw materials areharvested and understand the local and global ramifications.

Use Recycled Materials

Using recycle materials reduces waste and saves scarce land-fill space. Recycled materials also preserve the embodiedenergy of their original form, which would otherwise bewasted. This also reduces the consumption of materialsmade from virgin natural resources. Many building materials,particularly steel, are easily recycled, eliminating the needfor more mining and milling operations.

Use Materials with Long Life and Low Maintenance

Durable materials last longer and require less maintenancewith harsh cleansers. This reduces the consumption of rawmaterials needed to make replacements and the amount oflandfill space taken by discarded products. It also meansoccupants receive less exposure to irritating chemicals usedin the installation and maintenance of materials.

Building PhaseThe methods associated with the Building Phase strategy areconcerned with the environmental impact of actual construc-tion and operation processes.

Minimize Site Impact

Careful planning can minimize invasion of heavy equipmentand the accompanying ecosystem damage to the site. Excava-tions should not alter the flow of groundwater through thesite. Finished structures should respect site topology andexisting drainage. Trees and vegetation should only beremoved when absolutely necessary for access. For sensitivesites, materials that can be hand-carried to the site reduce theneed for excessive road-building and heavy trucks.

Employ Nontoxic Materials

The use of nontoxic materials is vital to the health of thebuilding’s occupants, who typically spend more than three-quarters of their time indoors. Adhesives used to make manycommon building materials can outgas — release volatileorganic compounds into the air — for years after the originalconstruction. Maintenance with nontoxic cleansers is also


important, as the cleaners are often airborne and stay within abuilding’s ventilation system for an extended period of time.

Post-Building PhaseDuring this phase, the architect examines the environmentalconsequences of structures that have outlived their usefulness.At this point, there are three possibilities in a building’s future:reuse, recycling of components, and disposal. Reuse andrecycling allow a building to become a resource for newbuildings or consumer goods; disposal requires incinerationor landfill dumping, contributing to an already overburdenedwaste stream.

Reuse the Building

The embodied energy of a building is considerable. It includesnot only the sum of energy embodied in the materials, butalso the energy that went into the building’s construction. Ifthe building can be adapted to new uses, this energy will beconserved. Where complete reuse of a building is not possible,individual components can be selected for reuse — windows,doors, bricks, and interior fixtures are all excellent candidates.

Recycle Materials

Recycling materials from a building can often be difficult dueto the difficulty in separating different substances from oneanother. Some materials, like glass and aluminum, must bescavenged from the building by hand. Steel can easily beseparated from rubble by magnets. Concrete can be crushedand used as aggregate in new pours.

Reuse Existing Buildings and Infrastructure

It has become common for new suburbs to move farther andfarther from the core city as people search for “space” and“nature.” Of course, the development of new suburbs fromvirgin woods or fertile agricultural fields destroys the veryqualities these suburbanites are seeking. Moreover, in additionto the materials for new houses, new development requiresmassive investments in material for roads, sewers, and thebusinesses that inevitability follow. Meanwhile, vacant landand abandoned structures in the city, with its existing infra-structure, go unused, materials wasted.



Principle 3:

Humane Design

Strategies

Preservation of Urban Design Design forNat’l Conditions Site Planning Human Comfort

Understand theimpact of designon nature

Respect topo-graphical contours

Do not disturbthe water table

Preserve existingflora and fauna

Avoid pollutioncontribution

Promote mixed-use development

Create pedestrianpockets

Provide forhuman-poweredtransportation

Integrate designwith publictransportation

Provide thermal,visual, andacoustic comfort

Provide visualconnection toexterior

Provide operablewindows

Provide clean,fresh air

Accomodatepersons withdiffering physicalabilities

Use nontoxic,non-outgassingmaterials

Figure 11: “Humane Design”methods of application.


Humane Design

As described in the introduction, this principle embodiesthree strategies: preservation of natural conditions, urbandesign and site planning, and design for human comfort.These strategies, in turn, yield specific design methods that willimprove the sustainability of architecture. Figure 11 showshow each method relates to the three strategies of HumaneDesign. These methods focus primarily on improving thequality of life for humans and other species.

Preservation of Natural ConditionsRespect Topographical Contours

The existing contours of a site should be respected. Radicalterraforming is not only expensive but devastating to thesite’s microclimate. Alteration of contours will affect howwater drains and how wind moves through a site.

Do Not Disturb the Water Table

Select sites and building designs that do not require excavationbelow the local water table. Placing a large obstruction (thebuilding) into the water table will disturb natural hydraulicprocess. If the water table is exposed during construction, itwill also become more susceptible to contamination frompolluted surface runoff.

Preserve Existing Flora and Fauna

Local wildlife and vegetation should be recognized as part ofthe building site. When treated as resources to be conservedrather than as obstacle to be overcome, native plants and ani-mals will make the finished building a more enjoyable spacefor human habitation.

Urban Design and Site PlanningThe methods associated with the Urban Design and SitePlanning strategy apply sustainability at a scale larger thanthe individual building.

Integrate Design with Public Transportation

Sustainable architecture on an urban scale must be designedto promote public transportation. Thousands of individualvehicles moving in and out of area with the daily commutecreate smog, congest traffic, and require parking spaces.


Promote Mixed Use Development

Sustainable development encourages the mixing of residential,commercial, office and retail space. People then have theoption of living near where they work and shop. This providesa greater sense of community than conventional suburbs.The potential for 24-hour activity also makes an area safer.

Design for Human ComfortProvide Thermal, Visual, and Acoustic Comfort

People do not perform well in spaces that are too hot or toocold. Proper lighting, appropriate to each task, is essential.Background noise from equipment or people can be distractingand damage occupants’ hearing. Acoustic and visual privacyalso need to be considered.

Provide Visual Connection to Exterior

The light in the sky changes throughout the day, as the sunand clouds move across the sky. Humans all have an internalclock that is synchronized to the cycle of day and night.From a psychological and physiological standpoint, windowsand skylights are essential means of keeping the body clockworking properly,

Provide Operable Windows

Operable windows are necessary so that building occupantscan have some degree of control over the temperature andventilation in their workspace.

Provide Fresh Clean Air

Fresh air through clean air ducts is vital to the well-being ofbuilding occupants. The benefits of fresh air go beyond theneed for oxygen. Continuous recirculation of interior airexposes people to concentrated levels of bacteria andchemicals within the building.

Use Nontoxic, Non-Outgassing Materials

Long-term exposure to chemicals commonly used in buildingmaterials and cleaners can have a detrimental effect on health.

Accommodate Persons with Differing Physical Abilities

One aspect of sustainable design is its longevity. Buildingsthat are durable and adaptable are more sustainable thanthose that are not. This adaptability includes welcomingpeople of different ages and physical conditions. The morepeople that can use a building, the longer the building’suseful life.

sustainable architecture module: introduction to sustainable design

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