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Buildings consume one-third of the total energy produced in the United States, produce 40 percent of the carbon dioxide emissions that have been linked to global warming and air pollution, and generate 33 percent of landfill construction waste. These statistics have resulted in a growing trend whereby buildings are designed, constructed, operated, reused, and deconstructed in ways that will enhance human health and protect environmental quality. Sustainable architecture is the expression coined for environmentally responsive building practices. It differs from conventional design by considering the environmental impacts of design decisions throughout the entire building life cycle from cradle to cradle instead of cradle to grave. It provides a comprehensive examination of all aspects of architectural design including site selection, energy conservation, passive solar strategies, low-energy systems, building materials, indoor air quality, water conservation, waste minimization, lighting, and use of renewable energies.
The roots of sustainable architecture can be traced to the ancient theoreticians that include Vitruvius, who in The Ten Books on Architecture discussed the benefits of designing with the local climate and indigenous materials (Morgan 1960). The skills of preindustrial builders, the mastery of using on-site resources such as proper orientation, thermal mass, shading, ventilation, and local construction materials, were all but abandoned after the invention of artificial lighting and air conditioning. Except for several notable exceptions (i.e., organic movement), architecture of the first half of the 20th century disregarded the environmental context of buildings. The energy crisis brought about by the 1973 Arab oil embargo hastened the return to energy-efficient design. The passive solar architecture movement of the 1970s responded by offering appropriate technical solutions that, for the most part, failed to address broader environmental and architectural concerns. The sustainability movement emerged in the late 1980s as an outgrowth of this period, adding to a heightened environmental awareness determined to achieve more comprehensive and integrated design solutions.
The term sustainability has its origins in the 1987 World Commission on Environment and Development report, Our Common Future. The concept was central to “a global agenda for change” in current development patterns focusing on both underdeveloped and industrialized countries. The term recognizes the interdependency of economic, social, and environmental factors necessary to sustain life on Earth. The defining quote from this report is: “Sustainable development seeks to meet the needs and aspirations of the present without compromising the ability to meet those of the future” (WCED 1987). Buildings and sites that utilize natural systems to minimize their global, regional, and local environmental impacts on land, energy, water, and materials form the basis of “sustainable” or “green” architecture. Human health, economic affordability, and social equity are also considered attributes of sustainable design.
Sustainable architecture involves both design philosophy and technology. Practitioners in the field have written manifestos, statements of principles, and guidelines to clarify the goals, intentions, and aspirations for sustainable design. One such widely published document is the Hannover Principles by William McDonough, named after the World’s Fair 2000 city in which the principles were drafted. The statements in this document elucidate the inherent value of nature and our need to seek a more symbiotic relationship with it. Guidelines for sustainable design by contrast tend to focus on applications of design strategies or technologies. The journal Environmental Building News of Brattleboro, Vermont, provides one such checklist, which serves as a concise listing of building design and construction practices for any home owner, builder, or designer interested in building sustainability.
Technologies for sustainable architecture form a long, cross-cutting list of alternatives that need to be adapted to local environmental conditions. Daylighting design (Guzowski 2000), passive solar heating (Mazria 1979), passive cooling (Givoni 1994), water recycling and reuse, and biological wastewater treatment are primary sustainable design strategies that combine innovations in technology with extensive design knowledge and expertise. Computer tools are still mostly segmented providing design assistance for particular building performance issues such as energy (Energy-plus, DOE2, and Energy- 10) and lighting design (Lightscape and Lumen-micro). A design tool that links disparate design and analysis components is Lawrence Berkeley National Laboratories’ Building Design Advisor. The Green Building Advisor by the Center for Renewable Energy and Sustainable Technology (CREST), E build, Inc., and Design Harmony, Inc. gives designers qualitative recommendations for sustainable design including bibliographic, video, and electronic resources as well as documented case study buildings.
Selection of building materials is another key focus of sustainable architecture. Construction materials and methods are sought that are low impact throughout the entire material life cycle; that is, the materials should create less environmental damage in their extraction, processing, use, waste, and disposal phases than conventional alternates. Green building materials typically have one or more of the following traits: they are durable, compostable, recyclable, re-usable, and nontoxic to humans. Many of the green building materials not only demonstrate superior environmental performance but also do not degrade indoor air quality when strict adherence to non-toxic content is heeded in installation as well as in the material. Recent history of sick building syndrome calls attention to the health risks of creating sealed buildings with insufficient ventilation and finish materials that cause chemicals to disperse into the indoor environment. In 1996 the American Institute of Architects published their guide to environmental building products called the Environmental Resource Guide. This book gave qualitative descriptions of the impacts of common building materials. Alternative building construction materials also play an important role in sustainable design (Elizabeth and Adams 2000). Straw bale (Bainbridge et al. 1994), rammed earth (Easton 1996), cob, recycled tires (Reynolds 1993), and fired ceramics (Khalili 1986) are the most familiar alternatives to conventional construction systems used in sustainable building.
There are a number of exemplary buildings that illustrate the principles of sustainable architecture spanning a wide range of building types, scales, and geographical locations. The examples presented here highlight the qualities that differentiate sustainable design from conventional practice.
The Center for Regenerative Studies at California State Polytechnic University at Pomona is an example of an integrated design solution demonstrating ecological site planning as well as sustainable building strategies. The project, built on 16 acres across from the main university campus, completed the first phase of construction in 1993 although design ideas originated in the classroom almost 20 years earlier under the tutelage of the late Professor of Landscape Architecture at Cal PolyPomona, John Tillman Lyle. Professor Lyle elaborated on the design process and solution in his book, Regenerative Design for Sustainable Development. The specific sustainable design strategies applied to the landscape include biological wastewater treatment through pond ecosystems, a solar farm with experimental solar electric technologies, habitat preservation for wildlife, and edible landscapes woven throughout the building site. The buildings were designed by the architectural firm Dougherty and Dougherty as demonstration facilities, with a variety of passive solar heating and cooling strategies. Building materials were selected for their durability, low maintenance, and low embodied energy. Recycled materials were used in the landscapes such as recycled tires for retaining walls and recycled concrete paving for outdoor patio spaces. The Center also enjoys its unique status as a social experiment for participatory student cohousing.
Another example of an integrated building and landscape solution is the passive solar subdivision, Village Homes, in Davis, California, by Mike and Judy Corbett that was started in 1975 (Corbett 1988). This 70-acre site with 220 homes manages storm water drainage using natural landscape features, narrow shaded streets to decrease exterior summer temperatures, a street layout that supports solar access, and edible landscapes throughout. Shared open space is developed between units adding to recreational use as well as a sense of community. Energy consumption for the passive solar homes in this subdivision is less than half that of conventional homes in the surrounding area. Less than 10 per cent of the homes use mechanical cooling, which is a testimonial to passive cooling in a climate that has many days reaching 100 degrees Fahrenheit in summer.
An example of a retail project utilizing the principles of sustainable architecture is the Real Goods Headquarters in Hopland, California. Real Goods, a retailer of renewable energy products, commissioned a building design that reinforced their corporate philosophy toward environmental stewardship. Architects from the Ecological Design Institute of Sausalito, California, designed a straw bale structure finished with “PISÉ” (pneumatically installed stabilized earth). The south-facing semicircular plan optimizes interaction with the sun, with tall clerestory windows on the southeast to capture morning light and shorter clerestories on the southwest to reduce late afternoon solar gain. An exterior trellis protects lower windows from the hot summer sun where visitors can enjoy the evaporative cooling effect from a water fountain in the entrance courtyard. Light shelves on the interior diffuse and reflect light creating a soft glow. Thermal mass is achieved through the concrete floor and interior PISÉ walls. The site has additional sustainable design elements, some built, others planned. There is a solar powered water pump at the entry, flow forms that can be used in water treatment as sculptural water elements, and retention ponds that form part of the landscape ecology. The parking lot utilizes biofilters to minimize the effects of nonpoint source pollution from automobiles. The restrooms for this complex are touted to passersby on the nearby highway as a “must-see.” Waterless urinals, recycled plastic toilet stalls, and reused toilet tank tops as wainscoting are the predominant features. This project and a more general discussion of the design team’s sustainable design philosophy are described in Ecological Design by Sim Van der Ryn and Stuart Cowan (1996) and A Place in the Sun by John
Shaeffer (1997).
To illustrate that sustainable design can be achieved in a more extreme climates, the
Rocky Mountain Institute in Snowmass, Colorado, ofifers an excellent example of combining home, office, and indoor farm into an exceptionally energy efficient and aesthetically pleasing environment. The owners, Hunter and Amory Lovins, have created a building that mirrors the resource-efficiency concerns that occupy their professional lives (Hawken, et al. 1999, Lovins 1977). Although the 4000-squarefoot building is located in a cold (8700 Fahrenheit heating degree day) climate, it is 99 per cent passively solar heated. The building, built in 1984, uses high-performance window technology, daylighting, energy-efficient electric lighting, high insulation levels, thermal mass, a sunspace, interior water features, and photovoltaics. The building boasts a ten-month payback period in energy savings to recover the initial cost of the energy improvements.
Office buildings, because of their emphasis on lighting and the high monetary value placed on the employees occupying these buildings, are a prime candidate for sustainable design. Worker productivity studies, as well as student performance in sustainable buildings, are beginning to connect design quality and occupant health, as illustrated in the studies by Dr. Judith Heerwagen of Seattle, Washington, and researchers at the Heshong-Mahone Group near Sacramento, California. Two notable office building examples discussed in more detail here are the ING Bank by Alberts and Von Huut and the C.K.Choi Building by Matsuzaki Wright Architects.
The ING Bank (formerly NMB) headquarters building near Amsterdam, the Netherlands is a corporate bank headquarters consisting of 10 vertical towers connected by a serpentine plan linking offices and support spaces. The towers use daylight, stack ventilation, plant materials, water features, and orientation devices to enliven as well as enhance the transition zones between buildings. Office workers are guaranteed natural light either from the exterior windows, with no worker being more than 20 feet from a window, or from the interior borrowed light. Site development includes several gardens placed in part to conceal a parking garage below. The building, built in 1987, is unique in terms of the participatory process used, which involved representatives from all future building occupant groups as well as all members of the design and consultancy teams from the beginning of the process. The 538,000 square foot building is also renowned for using 90 per cent less energy per square meter than the previous bank building, recovering the costs of energy improvements in energy savings after four months and reducing absenteeism by 15 percent (Roodman and Lenssen 1995). The bank is not only energy efficient, but it is also evocative in the variety of spatial experiences and environments it creates.
The C.K.Choi Building at the University of British Columbia utilizes a surprising array of bold and more common sustainable design strategies that are well integrated into the final design solution. The three-story 30,000-square-fbot office building has a long north- south axis to preserve adjacent forest land. Although this could pose a challenge for passive solar heating, the architects skillfully used roof forms to maximize north daylighting while creating a surface for mounting solar electric panels in the future. Reclaimed materials used in the building include salvaged wood trusses from a neighboring building undergoing demolition at the same time and recycled bricks. The architects experimented with a trickle ventilation system at the windows to encourage the infiltration of limited quantities of fresh air and utilized stack ventilation through the daylight atriums to avoid a conventional ducted ventilation system. The immediate landscape utilizes the building’s gray water. One of the building’s more unusual features for the building type is its use of composting toilets in an office building.
There are many more examples of sustainable office buildings worthy of further examination. These include the Audubon Building in New York City by the Croxton Collaborative, the Building Establishment (BRE) Headquarters in Hertfordshire, England, by Feilden Clegg Architects, the Menara Mesiniaga in Selangor, Malaysia by Kenneth Yeang, the Thoreau Center for Sustainability at the San Francisco Presidio by TLMS Architects, and an environmental studies building at Oberlin College in Ohio by William McDonough.
As seen in these projects, sustainable design goes beyond the energy savings goals of the 1970s by creating buildings that satisfy energy as well as ecological, aesthetic, and functional considerations through the overall design of building envelope, components, systems, and siting. Besides computer analysis of building systems, much of the decision- making and evaluation of sustainable architecture, however, is of a highly qualitative nature. Quantitative assessments that benchmark sustainable buildings for performance is a logical next step in the mainstreaming of sustainable architecture. A few of the current assessment methods are discussed next.
An attempt to combine economic and environmental measures for sustainable building materials has produced a number of computer-based life-cycle assessment tools. BEES, Building for Environmental and Economic Sustainability, from the National Institute of Standards and Technology allows comparative analysis of material selections on their environmental merit (e.g., global warming, ozone depletion, embodied energy) as well as their economic cost. Other life-cycle assessment tools, such as the Canadian product ATHENA, allow a detailed environmental accounting of a product throughout its entire manufacturing and use cycles in terms of energy, water, air, and solid waste effects. A concept called the “ecological footprint,” developed by Mathis Wackernagel and Bill Rees at the University of British Columbia, considers the far-reaching energy, water, and material resource effects involved in everyday patterns and products of consumption but does so in terms of replacement resources to ameliorate the environmental impact.
Another means for assessing environmental performance of sustainable architecture is through the use of green building rating systems. Rating systems assign building performance categories a value judged against a set of prescribed baseline criteria. Malcolm Wells’s 1969 Wilderness-based Checklist is one of the earliest rating systems using ecologically based accounting to tally the rewards of designs that improve environmental quality against the penalties of those with the opposite effect. More recently, the U.S. Green Building Council developed a national rating system called Leadership in Energy and Environmental Design (LEED). Regional adaptations to the categories in this system allow jurisdictions, such as cities, to tailor the ratings to their locality. Other examples of rating systems include the Austin, Texas, Green Builder Program and Building Research Establishment Environmental Assessment Method (BREEAM) in the United Kingdom.
Sustainable architecture developed in response to a cascade of environmental concerns of the late 20th century described by such authors as Rachel Carson, Donella and Dennis Meadows, Aldo Leopold, Buckminister Fuller, David Brower, Amory Lovins, Paul Hawken, and others. A series of international commissions, from the 1987 Bruntland Report to the 1992 Earth Summit’s Agenda 21, to the Montreal Protocol and the Kyoto Agreement, have crystallized the global importance of environmental issues that serve as a backdrop for design intervention. These concerns are echoed at the beginning of the 21st century when emerging fields such sustainable architecture, ecological engineering, sustainable agriculture, industrial ecology, and others begin to address the complexities of balancing environmental, economic, and social factors. Design decisions that affect land, energy, water, and material resource consumption, as well as human health and the human spirit, set sustainable design apart from conventional design and will continue to do so for years into the future.
MARGOT KALLY MCDONALD
Sennott R.S. Encyclopedia of twentieth century architecture, Vol.3 (P-Z). Fitzroy Dearborn., 2005. |
