Dovetail monitors development in green building, assesses stengths and weaknesses of established green rating systems for the purpose of promoting positive change, and engages in education regarding many of the programs and standards.
Over the last decade, the market for green building has experienced spectacular growth. According to a recent survey conducted by McGraw-Hill Construction, “the value of green home construction was $36 billion in 2013 and is expected to double by 2016, reaching $83-105 billion." Growth in green building has been even greater in non-residential construction. McGraw-Hill also recently reported that 41% of all nonresidential building starts in 2012 incorporated green building features, as compared to 2% of all nonresidential building starts in 2005.
Green building certification is a relatively new phenomenon, with the first major initiative developed about 25 years ago. The UK-based Building Research Establishment's Environmental Assessment Method (BREEAM) was established in 1990. BREEAM has the strongest scientific basis of any green rating system in the world, and is one of the world's most widely used green building rating system with over 250,000 certified buildings worldwide. The first national-scope green building rating system in the United States, the LEED program of the US Green Building Council, was launched a decade later. Scores of state and regional programs have come into effect since that time, with over 42 distinctly different green building rating systems in operation in the U.S. and Canada today. All green building rating systems began as, and today remain, voluntary programs. However, what was only several years ago an almost completely voluntary green building movement has now begun to be reflected in building codes.
Early green building rating initiatives in North America all were built upon lists of specific prescribed measures for reducing energy consumption and various environmental impacts. Arranged within categories such as Energy, Water, Indoor Air Quality, Materials and Resources, and Site, prescriptive lists of recommended or required measures for addressing specific concerns outlined the path toward environmentally better buildings. Each measure typically addressed a single concern or attribute such as recycled, recycled content, rapidly renewable, and local sourcing of materials.
Most of the green building programs in use in North America today continue to rely on prescriptive provisions. However, a shift away from prescriptive measures and toward performance and systematic assessment has begun. The foremost green building programs have made or are making major changes to move away from a prescriptive basis and toward a performance basis, with an emphasis on reliance on systematic, life cycle assessment (LCA) and LCA-based tools and sources of information. It is a major step forward, and a change that allows simultaneous, systematic, science-based consideration of multiple attributes rather than adherence to intuition-based single attributes.
As noted, voluntary green building rating systems are now beginning to find their way into building codes. The idea of incorporating green requirements into building codes is not new. Green requirements in city and county building codes in the United States date back to as early as 1985. The State of California became the first state to incorporate green building provisions into its California Building Standards Code; known as CALGreen, green standards are incorporated into the state building code and apply to all occupancies within the state. Model code language has also been developed in the form of ASHRAE 189.1 and the International Green Construction Code (IgCC), with provisions of these standards increasingly adopted by jurisdictions across the United States.