2010 California Residential Code (CRC; pp. 35-36):
The CRC requires the installation of CO detectors in new one- and two-family dwellings and townhomes of not more than three stories, and where work requiring a permit occurs in existing buildings. (Effective date: January 1, 2011)
CA Health and Safety Code, Division 13, Part 1.5, Chapter 2, Section 17926:
An owner of a dwelling unit intended for human occupancy shall install a carbon monoxide device, approved and listed by the State Fire Marshal pursuant to Section 13263, in each existing dwelling unit having a fossil fuel burning heater or appliance, fireplace, or an attached garage, within the earliest applicable time period as follows:
- For all existing single-family dwelling units intended for human occupancy on or before July 1, 2011.
- For all existing hotel and motel dwelling units intended for human occupancy on or before January 1, 2016.
- For all other existing dwelling units intended for human occupancy on or before January 1, 2013.