California has adopted the nation's first statewide green-building standards, which will become mandatory in 2010. The new California Green Buildings Standards Code requires builders to reduce energy use by 15 to 30 percent beyond current standards and use more recycled materials. Some of the code will be mandatory, while other parts are just suggested. This is a significant recognition that energy and resource conservation is essential for the welfare of state residents, and hopefully this officially sanctioned consciousness will spread to other states.
These new codes include basic passive solar mandates: "When site and location permit, orient the building with the long sides facing north and south. Provide exterior shade for south-facing windows during the peak cooling season. Provide vertical shading against direct solar gain and glare due to low altitude sun angles for east- and west-facing windows."
For renewable energy, the codes says, "Use 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."
For water conservation, the code says, "A schedule of plumbing fixtures and fixture fittings will reduce the overall use of potable water within the building by 20%, and provide water efficient landscape irrigation design that reduces by 50% the use of potable water beyond the initial requirements for plant installation and establishment."
"Each building shall further reduce the generation of wastewater by one of the following methods: The installation of water-conserving fixtures (water closets, urinals) or utilizing non-potable water systems (captured rainwater, graywater, and municipally treated wastewater
For materials to be specified for construction, the following is mandated:
- Select building materials or products for permanent installation on the project that have been harvested or manufactured in California or within 500 miles of the project site.
- Select bio-based building materials and products made from solid wood, engineered wood, bamboo, wool, cotton, cork, straw, natural fibers, products made from crops (soy-based, corn-based) and other bio-based materials with at least 50% bio-based content.
- Employ wood-based materials and products comprising at least 50% of a major building component, such as framing, flooring, or millwork, which are certified by one of five listed sustainably harvested certification programs.
- Use materials made from plants harvested within a ten-year cycle for at least 2.5% of total materials value, based on estimated cost.
- Use salvaged, refurbished, refinished, or reused materials for a minimum of 5% of the total value, based on estimated cost of materials on the project.
- Use materials, equivalent in performance to virgin materials, with post-consumer or preconsumer recycled content value (RCV) for a minimum of 10% of the total value, based on estimated cost of materials on the project.
- Use cement and concrete made with recycled products, fly ash, raw or calcined natural pozzolan, blast furnace slag (as a lightweight aggregate) .
- Select materials for longevity and minimal deterioration under conditions of use.
- Select materials that require little, if any, finishing.
- Select materials that can be re-used or recycled at the end of their service life in the project.
- Select materials assemblies based on life cycle assessment of their embodied energy and/or green house gas emission potentials.
- Provide readily accessible areas that serve the entire building and are identified for the depositing, storage, and collection of non-hazardous materials for recycling, including (at a minimum) paper, corrugated cardboard, glass, plastics and metals.
Environmental and health-related items establish specific limits on VOC emission of materials used within the structure, as well as regulate ventilation, CO2 emissions, tobacco smoke, lighting, outside views, and noise transmission.
Additional recommended measures include:
- If feasible, disassemble existing buildings instead of demolishing to allow reuse or recycling of building materials.
- Utilize a Frost-Protected Shallow Foundation.
- Use pre-manufactured floor and roof systems to eliminate solid sawn lumber whenever possible.
The code also identifies site improvements including bicycle storage and designated parking spots for low-emissions vehicles.
I have been advocating most of these measures at www.greenhomebuilding.com for many years now, and it is heartening to see them being officially sanctioned. This is a far-reaching and well-considered attempt by California legislators to establish requisites for living sustainably. If there are going to be building codes, they might as well be green! Yeah California!
- from July 22, 2008