As if we didn’t have enough code books taking up valuable space on our bookshelves, the powers that be have adopted a new residential building code for California, to take effect on January 1, 2011. I just went to an all day class on this new code, the California Residential Code, 2010 edition (henceforth known as the CRC), and thought I would share some of the information while my head is still spinning. The revisions to current standards promise to be variously useful and annoying. Along with the new 'CalGreen' code, also to take effect in January, we are in for a bit of a learning curve (more about CalGreen in the next blog).
The new CRC does not supercede the current California Building Code (2007 edition), but rather supplements it, sandwiching a new Part 2.5 into the existing structure of the CBC. The CRC will govern most residential construction, including single and duplex residential structures, live work units (when built as houses), semi-attached townhouses, and certain kinds of group care facilities. It does not cover other residential projects such as apartments, condos, hotels, and so forth, which will still be covered by the larger CBC. Incidentally, the CRC is based on the International Residential Code (as the CBC is now based on the International Building Code). Most of the U.S. is using some version of these codes now, so we are gradually creeping towards a national standard. San Francisco, wouldn’t you know, seems to be the one locality that has not adopted the new CRC, so none of these changes are pertinent here.
The new CRC is a sort of one-stop-shop, containing most of the pertinent code information for the most typical kinds of residential construction – up to two story wood frame structures, plus basements and habitable attics, on concrete foundations. In general, if there are conflicts between the overall code and the new CRC provisions, the more detailed CRC rules apply. On the other hand, the CRC only covers very basic, standard kinds of structural designs, so one can defer back to the CBC for more more specific structural engineering problems.
Some of the more significant changes are as follows:
- Accessory structures up to 120 square feet are exempt from needing a permit (though they are expected to meet code requirements) and don’t need to meet fire separations for windows to property lines and other buildings.
- Requirements for fire resistance of walls and size of windows based on separation from property lines have been somewhat relaxed. Likewise, requirements for fire resistance inside structures and from garages to houses have been reduced.
- Requirements for fire blocking – construction elements that stop the spread of fire within structures – have generally been made stronger.
- Habitable attics are no longer considered a ‘story’ for code purposes. Converting an attic to habitable space does not therefore constitute adding a floor to a building – so one doesn’t necessarily need to upgrade the seismic strength of the entire building. This will make it easier to build, and retrofit, attics as useable spaces.
- Minimum ceiling height for habitable rooms has been reduced to 7’-0”. This is quite important for those who have existing basements and attics with low head clearance. Suddenly, thousands of dollars in structural remodeling may not be necessary to get that rec room or home gym that you wanted.
- Fire sprinklers are now required on all new residential projects; remodels and additions may need sprinklers depending on local ordinances. This is a huge change, very controversial apparently because of its cost. On the other hand, most municipalities in the Bay Area already require this, so possibly not a big deal locally.
- Carbon monoxide alarms will be required in most dwellings, and the rules for smoke detectors are more stringent. Systems in new construction need to be interconnected, powered by building electricity (with battery back-up).
- Handrails on stairs may have the traditional wider shape, not just the cylindrical type required by the CBC.
- Guardrails are required not just when the adjacent ground surface directly below an edge is more than 30” lower, but if the ground surface within 3 feet of the edge horizontally is more than 30” lower.
- Un-vented roofs and (minimally) un-vented crawlspaces are allowed if certain measures are taken regarding vapor transmission.
There are literally hundreds of very detailed changes, so contractors and design professionals will need to carefully review the pertinent sections of the new code. So call us up! (or take a class). The particular class I took was taught by the incredibly knowledgeable Douglas Hanson, who is responsible for the “Code Check” series of books which makes all this information easily accessible. Copies of the new codes are available locally from the sponsor of the class, the wonderful Builder’s Booksource in Berkeley . A visit there is more than likely to fill up any spare bookshelf space with even more interesting tomes.
Check the California Building Standards Commission website for other information.