Cal. Gov. Code § 65852.4
A city, including a charter city, a county, or a city and county, shall not subject an application to locate or install a manufactured home certified under the National Manufactured Housing Construction and Safety Standards Act of 1974 (42 U.S.C. Sec. 5401 et seq.) on a foundation system, pursuant to Section 18551 of the Health and Safety Code, on a lot zoned for a single-family residential dwelling, to any administrative permit, planning, or development process or requirement, which is not identical to the administrative permit, planning, or development process or requirement which would be imposed on a conventional single-family residential dwelling on the same lot. However, a city, including a charter city, county, or city and county, may require the application to comply with the city's, county's, or city and county's architectural requirements permitted by Section 65852.3 even if the architectural requirements are not required of conventional single-family residential dwellings.
Ca. Gov. Code § 65852.4