Building green:
an overview of sustainable design
and the LEED rating system
By Roxanne Button
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Green construction at Niagara University
Photo couresty of Cannon Design. |
This dependence on building systems has gotten us to where we are today. Buildings use a tremendous amount of energy, water, and materials. The 2003 U.S. DOE Buildings Energy Databook reported that buildings consumed thirty-nine percent of total energy and seventy percent of total electricity. Statistics from 1995 stated that buildings used forty percent of the world’s raw materials. The EPA reported two years later that approximately 136 million tons of construction and demolition waste were generated in this country in one year. That’s almost sixty-five percent of the total municipal solid waste that was produced that year.
Statistics like this—reported on a national or global scale—can be daunting as we try to understand our own environmental impacts. We need to take these greater environmental challenges and bring them down to a scale that is easier to deal with. Environmentally sustainable design tries to do that by working at the level of neighborhoods and individual buildings. That’s where the U.S. Green Building Council (USGBC) and LEED come in.
The goal of sustainable design is to minimize the impacts of the built environment on the natural environment, and the purpose of LEED is to measure those impacts. LEED, that stands for Leadership in Energy and Environmental Design, was developed by USGBC in 2000 as a tool to evaluate buildings. It’s a rating system—often compared to a nutritional label for buildings—that assesses the “greenness” of a building against a specific set of criteria.
LEED is a voluntary and consensus-based standard which has been adopted by many cities, state and local governments, corporations, and federal government agencies. New York State, for example, requires that its buildings meet Executive Order 111, which sets energy standards and requires that buildings be designed according to LEED criteria. LEED has also been adopted in Canada, India, Brazil, and almost a dozen other countries.
More than 1,100 buildings have become LEED-certified, and well over 9,000 are registered in the system. New York State has more than thirty-five certified buildings, and the Buffalo area is home to at least five of those, with more to come. In addition to certifying buildings, the USGBC has three professional accreditation exams that have been taken by more than 45,000 building industry professionals.
LEED encompasses almost every aspect of a building from sites to materials. What started as one all-purpose rating system has evolved into a family of systems that address the needs of particular building types (such as LEED for schools).
All rating systems include a checklist and are organized into six categories: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, and Innovation and Design Process. Each category has a list of credits that are worth points towards certification. There are four different levels of LEED certification: Certified, Silver, Gold, and the highest achievable level, Platinum. The most-used and best-known of the LEED family is New Construction (NC). Basic certification under LEED-NC requires a minimum of twenty-six points, while a Platinum building needs at least fifty-two points. Because of the structure of the rating system—similar to a menu in a restaurant—it is impossible to get all sixty-nine available points.
The first step towards certification is to register the project online with USGBC and pay a registration fee based on total square footage. Very early in the project the design team establishes sustainability goals which develop into design strategies and relate to particular LEED credits. As the project moves into construction, the sustainable features of the building are documented to prove that the project has met LEED’s standards. When the project is completed, the documentation is submitted online to USGBC, along with an application fee. Certification is then awarded based upon the final points total, and a plaque is presented to the building owners.
Traditionally, building design has been a linear and segmented process, where most team members focus on their own area of expertise. Sustainable design demands that everyone on the team work together through an integrated and collaborative design process from start to finish, feeding off of each other’s expertise. For architects and designers, it is the synergies that develop out of this collaboration that provide the greatest potential for sustainability, and for the most exciting design opportunities.
For our clients, LEED’s greatest value is that it is a third-party certification. Any architect can tell clients they are getting a green building, but how do you really prove that? LEED’s review and certification process ensures credibility. In just seven years, it has become the industry standard.
Clients benefit from lower operating costs and better working and living environments. Students have healthier and better schools. Homeowners have more efficient, comfortable houses.
Buildings used to be designed to respond to the natural cycles of wind and sun, and to last hundreds of years. Green design, which is based on the premise that everything is interconnected, is bringing those fundamentals back into architectural practice. LEED helps to promote common-sense strategies like reducing energy and water usage, reusing buildings, and using low-impact materials. Those of us who champion green design believe that we have finally passed the turning point: it’s not a question of why should you build green, but why wouldn’t you?
Roxanne Button is an architect with AIA, MRAIC, LEED AP.
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