In our last installment on “Sustainable Urban Environments”, we discussed challenges and opportunities which the AEC industry will face in order to create sustainable urban environments amid aging infrastructure, with a workforce constrained by demographic and skill shifts, and in response to client pressure for highly productive and cost-effective results. Next we look at emerging opportunities for change and consider how communities and practitioners can leverage past and present design approaches to increase sustainability of our buildings and infrastructure.
Design Imperatives
Last November, the 2007 Greenbuild Expo in Chicago attracted an unprecedented number of attendees – over 22,500 people from all spheres of design, engineering, construction, real estate, product manufacturing and other green-related fields. In his keynote presentation to this audience, Rick Fedrizzi, President and CEO of the United States Green Building Council, linked the rapid growth of the expo audience to a worldwide movement of concern and commitment to improve the built environment. The movement is clearly global, according to Fedrizzi, engaging participation in the USGBC’s LEED (Leadership in Energy and Environmental Design) rating system by fifty-one countries, with many more communities likewise connected through use of worldwide rating systems such as BREEAM (Building Research Establishment Environmental Assessment Method), CASBEE ™ (Comprehensive Assessment System for Building Environmental Efficiency), Green Globes, Green Star and others.
{sidebar id=199 align=right} In the past, architects sought inspiration from vernacular architecture, seeking design practices which reflected knowledge held by the creators of built environments throughout history. In the 1930s and 1940s, George Keck designed a passive solar house for the 1933 Chicago Expo and, later, a house for Howard Sloan which was dubbed “passive solar .” These techniques were rediscovered in the late 70’s and early 80s during a time when energy shortages raised awareness about the value of traditional approaches to passive solar design to address the resource crises of the time. Popular texts such as Ed Mazria’s “Passive Solar Energy Book” [1] and Ian McHarg’s “Design with Nature”[2] increased awareness of these techniques and expanded their adoption.
Today, we observe the rapid global adoption of sustainable standards and policies. Practitioners are motivated to grasp the opportunity represented by the move away from a carbon economy, as highlighted during a Greenbuild keynote by former United States President William J. Clinton. However, for long-term efforts toward sustainability to be meaningful, they must consider the full lifecycle of environmental structures and be achieved at a myriad of scales – from infrastructure to community to neighborhood to building to component.
These broad physical and time scales encompass an overwhelming array of issues. To enable designers and planners to systematically address this overwhelming array and make strides toward sustainability, rating systems such as BREEAM,
LEED and others represent concrete frameworks which convert the fundamental imperative – reduce the consumption of limited resources throughout the project lifecycle – into specific guidelines and recommendations which designers and planners can pursue. Once a sufficient number of these options are integrated into a specific project, confirmed by independent authorities, the project receives a certification or other official stamp that indicates sustainable design achievement. Public concern with the crisis of global warming leads owners, occupants and community leaders to find value in this official stamp. We are seeing more and more evidence of the way that sustainable certification attracts occupants to purchase and lease sustainable buildings and developments. Also, experts are better able to calculate the lifecycle cost savings from these projects due to reduced consumption of costly energy. The market is beginning to drive adoption of sustainable design.
{sidebar id=200 align=left} Since their inception in the 80s, rating and assessment systems have expanded to address the need for sustainable consideration across the project lifecycle for a growing number of building and infrastructure development types. Recently, the BREEAM organization announced the advent of “BREEAM Developments ”, an application of that assessment approach to urban development. BREEAM Developments will extend the checklist for sustainable development published by the BREAM in 2002.
In 2009, the USGBC will release a variation of the LEED rating system for neighborhoods, LEED-ND , moving the focus from a building and site outward to a community perspective. Over two hundred projects ranging from an acre to over 12,000 acres are participating in the pilot phase of the neighborhood scale LEED rating process. Similarly, CASBEE has announced CASBEE-UD (urban development). At the scale of the community or neighborhood, sustainability integrates smart growth with new urbanism and combines the specifics of green building design along with green site design engineering criteria with these planning principles .
The major design points of LEED for neighborhoods are grouped into three main categories – location, pattern and construction. LEED-ND’s “Smart Location and Linkage” requires that teams locate projects near existing water and wastewater systems and plan for ways to capture rainwater and reclaiming of grey water for non-potable uses (such as irrigation), thus helping to reduce the project’s impact on existing drinking water systems. Siting should factor in avoidance of habitats for imperiled species and other ecological factors, and conservation of wetlands and agricultural land and avoidance of floodplains helping to balance ecological biodiversity with the social needs of the local population.
Reducing automotive dependence raises project success with LEED-ND, such as by providing direct access to public transit, to housing and jobs, bicycle networks, and schools. “Neighborhood Pattern and Design” recommends that projects inspire compact and open communities, with affordable housing and diverse uses. Neighborhoods should be designed to accommodate walkability, access to transit and public space. “Green Construction and Technology” considers site factors such as minimization of site disruption through design, brownfield reclamation and remediation, and construction pollution reduction. Other green construction factors include the considerations which are prominent in LEED for New Construction (NC) – improved management of energy, water, wastewater and waste, reuse of buildings, maximizing green spaces, minimizing heat island impact of buildings, streets and parking lots and actual certification of project structures through LEED-NC.
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In summary, projects qualify for LEED-ND certification by demonstrating wise management of the site and community to increase walk-ability and access to public transit, mixed uses, and attentiveness to site conditions relative to natural habitats. Innovation and design process provide opportunities for projects to be recognized for successful alternative approaches by LEED-ND, as they are in all LEED variations. As these urban / large scale rating and assessment systems arrive on the scene, their success may well follow the pattern of analogous systems applied to individual buildings.
The BREEAM website states that 77,000 buildings have been certified under the BREEAM assessment method to date . The BREEAM assessment of buildings considers nine areas – management, energy, health, pollution, transport, land use, ecology, materials and water. The BREEAM process is focused on nine building types – homes, healthcare, industrial, multi-residential, prisons, offices, retail and schools, with a tenth category, “bespoke”, for projects outside this list. BREEAM international is available for new building types or for country- or region-specific applications.
By comparison, the USGBC has certified 3.2 billion square feet of built space. Building projects for new interior and commercial building construction, homes, schools, retail, health-care and core and shell can pursue variations of the USGBC’s LEED rating system targeted to the specific concerns of each building and construction type. Acknowledging the large stock of existing buildings which must be modified to achieve a truly sustainable built environment, the USGBC encourages certification under LEED for existing buildings (LEED-EB) to designate sustainable operations. Other rating systems and tools (CASBEE, Green Globes TM , Energy Star and GreenStar continually add to the list of individual buildings with desirable sustainable characteristics.
CASBEE’s focus includes energy, resources, local and indoor environments. New chapters of these standards groups and completely new organizations are growing around the world. The German Green Building Council (DGNB ) launched in 2007 and is making rapid strides toward industry awareness and adoption of a new certification system for that country. The World Green Building Council emerged to further international communication, exchange and standards development and adoption as the green building councils in individual countries grew in influence. Though each one of these organizations is focused on a particular community with a unique point of view about sustainability, they share the common goal of driving adoption of sustainable practices and encouraging the completion of high quality design projects.
Sustainable Practices
What are the practices and methods which underlie high quality sustainable design? Both BREEAM and USGBC have established education programs which encourage any individual who contributes or has an interest in the building process to become an assessor or become accredited in a particular system. These programs’ educational focus is building knowledge of the assessment methods and rating systems themselves. Relevant knowledge in important sustainable characteristics of built projects and the underlying scientific principles is required to achieve the accepted attributes of sustainability, but these programs stop far short of mandating a specific approach to the design process itself. The goal is to raise awareness of interdependencies of design systems, to look at a project holistically rather than through a specific trade’s lens. This allows for designed systems and approaches to work in unison rather than compete against on another in application.
{sidebar id=202 align=right} Although sustainability standards organizations do not necessarily lay out formulaic design processes, they each embody a philosophy about sustainable design described by the specifications of certification criteria. Each system reflects the imperative of reducing the non-replaceable consumption of natural resources with a strong focus on efficient use of energy sources. Along with developing standards and frameworks to codify the practice of sustainable design, these organizations work with planners, designers, developers and policymakers to expand the pool of educated and experienced practitioners.
Additionally, a growing set of formal academic degree offerings, sustainability accreditation programs, professional workshops, and practical reference guides and texts offer practitioners access to useful insights. Daniel Williams’s “Sustainable Design” [3] delves into the best practices revealed by the American Institute of Architects’ Committee on the Environment’s (AIA-COTE ) award winning projects from 1997-2006.
Starting with the notion of sustainable design as fitting into an ecological model, Williams lays out three core principles, which he calls “scalar elements” to be considered in the initial phase of design – “Connectivity”, “Indigenous”, and “Long life, loose fit”. According to Williams, “the regional design process starts with the gathering of information on the natural and existing patterns and conditions of the biomes and natural systems” (Williams, 2007). He advocates the use of urban system maps to illustrate site characteristics such as use of public space, transportation strategies, building codes, user populations, and other important factors. Overlapping these maps yields insights about the site which can be depicted as “systems conflict maps”.
Douglas Farr, chair of the USGBC’s steering committee for LEED for neighborhoods task force, offers concepts and case studies for the design of sustainable communities, which he calls “sustainable urbanism” (Farr, 2008 [4]. Farr’s approach starts from a definition – “sustainable urbanism uses knowledge of human and natural systems to integrate walkable and transit-served urbanism with high performance buildings and high-performance infrastructure” (Farr, 2008). The design practices which Farr advocates and illustrates throughout the book emphasize leadership and communication so that designers and planners can work with communities to develop a vision for a sustainable community, complete with evaluative criteria and performance targets.
Educational institutions are incorporating sustainable methods into established professional degree programs. This is a challenge, since curricula for these programs are already tightly packed with a dense accumulation of competency requirements. Yale University offers a graduate program in sustainable design from urban to regional scale focused on ecosystem impacts and benefits ranging from site to globe. The program is a joint offering from the Yale School of Architecture and School of Forestry and Environmental Studies and includes coursework from the professional architecture program along with environmental offerings. Similar changes have gained a footing in other schools such as Colorado State University in Fort Collins. At that institution’s School of Global Environmental Sustainability the focus is on the engineering side of sustainable design – approaches such as grey water capture and recharge systems, engineered wetlands for treating wastewater on site and capture, metering and filtration systems for storm water runoff to runoff into city stormwater systems.
Building Information Modeling (BIM) for Sustainable Performance
Sustainable design methods have evolved to reflect the need for more rigorous data to support performance evaluations. We have observed the industry shift toward technology-based desgn methods, and more recently, the advent of innovations in digital modeling. Information models of environmental conditions and design scenarios & proposals can be linked with accurate information about sustainable characteristics, providing opportunities for improved decision-making.
Building Information Modeling (BIM) now enables designers and planners of built environments to envision and assess the sustainable characteristics of buildings, infrastructure and communities before they are built. In-depth analysis and simulation of light, water, site conditions, properties of construction materials, and their interactions are possible in the preliminary conceptual design stages providing designers with the ability to create, predict and deliver a design aimed at harmonizing with its surrounding environment. And following conceptual design, building information models (BIM) reflecting both horizontal (civil) and vertical structures evolve throughout the design process, are developed and refined increasing in their capacity to support more rigorous analysis.
This analysis enables assessment of design options and predictions about whether a particular design alternative will achieve the required performance during construction, occupancy and use. Analysis also provides a means by which the various stakeholders and designers of the project can review change impacts on their peers in the project team, helping to resolve issues early and enhancing collaboration around goals and objectives of the project. Visualization of the analytical results improves client understanding and designer-client-occupant communications.
{sidebar id=203 align=left} A focus on built environments that are sustainable has led many to consider better ways to measure and design for improved performance around carbon emissions, water use and waste reduction. Aggressive reductions in the energy consumption and emissions of the built environment have been made a focus of the industry. Initiatives such as Architecture 2030 make a compelling case that the world is poised at a moment of climate change crisis, and that the design and construction industry must create buildings, infrastructure and communities which are “net zero”, which consume no more energy than they produce, by the year 2030.
This has been paralleled by other efforts to create zero water footprints where reclaiming rainwater, and recycling of grey water for non-potable uses minimizes impact on existing infrastructure reducing loads on this aging infrastructure. With the recently enacted H.B. 1141, the Colorado General Assembly took an important first step in ensuring such reliable water supplies for new development. This law creates a new tool for local governments to determine whether development projects can demonstrate that a proposed water supply is adequate to meet a project’s water supply demands. It gives local governments the authority to deny developments without adequate water supplies, but local governments retain discretion to decide whether to authorize development.
Organizations emphasizing sustainability are moving more aggressively to incorporate life cycle analysis with a focus on carbon emissions, water footprint and material reuse. The USGBC recently announced that the Aldo Leopold Centre in Wisconsin, a 2008 AIA-COTE award winning project, was designated a net zero or “carbon neutral building” and received the LEED Platinum certification with the highest number of points (61 of a possible 69) to date. It is now possible f or projects to conduct assessments on the degree of carbon neutrality, actively amending design alternatives to come closer to that goal of being net zero. This is an exciting example, which illustrates that the movement toward built environment sustainability is achievable.
Rating systems play an important role in clarifying the best practices and required characteristics for a sustainable built environment, and in creating a market demand for sustainable design. Innovative technologies provide data and methods which enable designers and planners to adopt best practices. When the USGBC convenes Greenbuild Expo in Boston in November 2008, that organization anticipates yet another significant leap in the number of attendees and the level of commitment and urgency for sustainable products, methods and inspiration. As practitioners adopt innovative processes, armed with digital models, data, and analytic tools, there is an opportunity not only to create new roles for our professions, but also to respond to the greatest design imperative – to realize a built environment which can sustain us through many, many generations.
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By Erin Rae Hoffer, AIA LEED® AP CSI & Terry D. Bennett, PLS, LLS, LPF, LEED® AP , Autodesk
References
[1] Mazria, Edward , “Passive Solar Energy Book”, Rodale Press, 1980
[2] McHarg, Ian L., “Design with Nature”, Doubleday, 1971, reissued by Wiley in 1995
[3] Williams, Daniel E. FAIA, “Sustainable Design: Ecology, Architecture and Planning”, John Wiley & Sons, Hoboken, NJ 2007
[4] Farr, Douglas, “Sustainable Urbanism: Urban Design with Nature”, John Wiley & Sons, Hoboken, NJ 2008
