California Code, Health and Safety Code - HSC § 17959.3

(a) It is the intent of the Legislature to encourage the use of passive solar energy design. The Legislature recognizes that building code regulations with regard to natural light and ventilation standards have to be modified to permit existing buildings to be retrofitted with passive solar energy.

(b) Notwithstanding Section 17922, any city or county may by ordinance or regulation permit windows required for light and ventilation of habitable rooms in dwellings to open into areas provided with natural light and ventilation which are designed and built to act as passive solar energy collectors.

(c) On or before September 1, 1999, the department shall, after consulting with the State Energy Resources Conservation and Development Commission, prepare, adopt, and submit building standards to implement the provisions of this section for approval as part of the California Building Standards Code pursuant to Chapter 4 (commencing with Section 18935) of Part 2.5.