California Passes Green Statewide Building Code

Aug. 1, 2008
California has approved the first statewide green building code in the nation. The code will take effect in 2010 and will apply to single-family homes, state buildings, heath facilities and commercial buildings.

Sacramento, Calif. — California has approved the first statewide green building code in the nation. The code will take effect in 2010 and will apply to single-family homes, state buildings, heath facilities and commercial buildings.

The code's final version will be published in the California Code of Regulations, Title 24, Part 11. Unless otherwise provided for by the Building Standards Commission, the code will be effective 180 days after publication. The code can be downloaded in Adobe PDF format from the Commission's Website (

The code will apply to all buildings for which applications for building permits are submitted after the code is effective. Cities and counties also may make changes to account for local climactic, geological or topographical conditions, and which may be stricter than the statewide code.

The code includes both mandatory and optional requirements, noted construction attorney Allen Matkins of Leck Gamble Mallory & Natsis LLP. Many of the optional requirements concern residential building and will become mandatory in the 2010 edition of the code. The requirements that will be mandatory in 2010 relate to planning and design, energy efficiency of the building, air sealing of the building, water efficiency and conservation, material conservation and resource efficiency, and indoor environmental quality, Matkins said. According to the Building Standards Commission, the standards, when fully implemented, will create structures that are the equivalent of the U.S. Green Building Council's Leadership in Energy and Environmental Design rating of Silver.

The code has been characterized as confusing, which may be a fair assessment. The online version of the code is color-coded seven different ways because sections of the code have been adopted by different California state agencies. The text in violet has been adopted by Office of Statewide Health Planning and Development for hospital and healthcare construction. Text coded black, dark yellow or orange has been adopted for residential construction by the Department of Housing and Community Development. Printed copies of the code come in black-and-white.

The code requires on-site renewable energy sources such as solar, wind, geothermal, low impact hydro, biomass and bio-gas for at least 1% of the electric power or 1kW, whichever is greater.

The code requires that indoor water use be cut by 20%. The designer would have to create a schedule of plumbing fixtures and fittings that will reduce the overall use of potable water within the building by 20%. The reduction is based on the maximum allowable water use as required by the current California Building Standards Code, such as 1.6-GPF toilets. The 20% reduction in potable water use can be demonstrated by either installing low-consumption fixtures or by calculating a 20% reduction against a “water use baseline.” For low-rise residential occupancies, the calculation is limited to water closets, urinals, lavatory faucets, showerheads and kitchen faucets. Large residential or commercial occupancies get into metering faucets and washfountains.

The baselines assume that plumbing fixtures would meet the minimum required by law, such as 2.5-GPM for showerheads, 2.2-GPM for lavatory and kitchen faucets, and 1.6-GPF for toilets.

A calculation based on water usage would multiply the flow rate of the fixture or fittings times the number of minutes used or uses per day, multiplied by the number of occupants. For example, the baseline for a showerhead would be 2.5-GPM times eight minutes times the number of occupants in the building. The designer would have to demonstrate a 20% water use reduction from that. Or, the easy way to handle it is to simply install 2.0-GPM showerheads. The same calculation for toilets would multiply flushes per day and the number of occupants, or else the designer can simply specify 1.28-GPF high-efficiency toilets.

The combined flow rate of all showerheads cannot exceed the limit set by the 20% reduction, or else the shower system controls have to limit flow to one 2.0-GPM fitting at a time.

Each building will be required to reduce the generation of wastewater by the installation of water-conserving fixtures or by using non-potable water systems, such as captured rainwater, graywater, and municipally treated wastewater. New buildings and facilities will have to be dual plumbed for potable and recycled water systems for toilet flushing when recycled water is available as determined by the local enforcement authority.

The code requires an energy factor for a gas-fired storage water heater of 0.62 or higher and an energy factor for a gas-fired tankless water heater of 0.80 or higher. Hot water lines must be insulated with a minimum of R-6 insulation.

Hot water distribution systems should minimize the amount of water that goes down the drain by using methods or features such as an on-demand hot water recirculation system; a point-of-use hot water system; a centrally located water heater to minimize the length of piping between the fixtures and water heater; and hot water piping sized to meet the minimum pipe size diameters allowed by the California Plumbing Code.

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