(a) Except as otherwise provided in sections 18300, 18303, and 18304, Health and Safety Code, the provisions of this chapter shall apply to the construction, use, maintenance, and occupancy of mobilehome parks, mobilehome and special occupancy lots, permanent buildings, accessory buildings or structures, and building components wherever located, both within and outside of mobilehome parks, in all parts of the state. These provisions shall also apply to the use, maintenance, and occupancy of manufactured homes, mobilehomes, multifamily manufactured homes and recreational vehicles, and the installations for supplying fuel gas, water, electricity, and the disposal of sewage from accessory buildings or structures, building components, recreational vehicles, manufactured homes, multifamily manufactured homes and mobilehomes wherever located within mobilehome parks, in all parts of the state.

(b) Provisions that apply only to Special Occupancy Parks, or separate designated special occupancy park sections within a park, are located in Title 25, California Code of Regulations, Division 1, chapter 2.2 of this division.

(c) Existing construction, connections, and installations of units, accessory buildings and structures, building components, plumbing, electrical, fuel gas, fire protection, earthquake resistant bracing, and permanent buildings made before the effective date of the requirements of this chapter may continue in use so long as they were in compliance with requirements in effect at the date of their installation and are not found to be substandard.