California Adopts Voluntary Green Building Standards

By Alyson Wendt

California has become the first state to adopt green building standards into its building codes. The standards, adopted by the California Building Standards Commission, will become part of Title 24, the state’s building and energy-efficiency regulations, in July 2009. Different building types—governed by separate agencies in California—are covered by different portions of the standards. Overall, the requirements for residential buildings are less stringent than those for commercial buildings. Although currently voluntary, the standards will become mandatory in 2011 after another round of code reviews.

The new standards raise the bar for energy efficiency: to meet them, commercial buildings must use 15%–30% less energy, depending on building type, than a comparable building built to California’s already stringent code. These buildings must also meet 1% of their total energy use with onsite renewable generation. Residential buildings must meet energy code requirements and include air-sealing measures defined in the legislation.

New buildings designed to meet the voluntary standards must also demonstrate 20% savings in indoor potable water use compared with current code requirements. The residential standards limit the use of multiple showerheads in a single shower, making them among the earlier codes to regulate this loophole that circumvents federal limits on showerhead flow rates. Outdoor water use in commercial buildings must be reduced by 50% compared with a building constructed to code. The standards also contain provisions for rainwater collection and graywater irrigation, as well as dual plumbing in commercial buildings for potable and recycled water.

The standards require design teams of commercial buildings to select biobased materials, defined as rapidly renewable materials and certified wood. According to the provision, rapidly renewable materials must represent 2.5%, by cost, of the materials used in a building. The certified wood provision does not specify a percentage requirement but does reference several certifying bodies, including the Forest Stewardship Council (FSC) and the Sustainable Forestry Initiative. The Northern California chapter of the U.S. Green Building Council (USGBC-NCC) objected to the provision during the public comment period, citing a lack of definitions for the term “biobased” and a lack of stringency in forest certification programs other than FSC.

Finally, the standards include extensive indoor environmental quality requirements for commercial buildings. California has already placed limits on formaldehyde emissions from composite wood products. The green building standards add increased ventilation, daylighting, and occupant control of thermal and lighting comfort to the equation for commercial buildings. The standards for residential buildings are less stringent, requiring only that homes meet the formaldehyde regulation and avoid paints, adhesives, carpets, and other materials with high levels of volatile organic compounds.

This article was produced by BuildingGreen, LLC.- www.buildinggreen.com