Sequoia Park Associates v. County of Sonoma

One of the subjects covered by the Subdivision Map Act (Gov. Code, § 66410 et seq.) is the conversion of a mobilehome park from a rental to a resident-ownership basis. One of the provisions on that subject is Government Code section 66427.5 (section 66427.5), which spells out certain steps that must be completed before the conversion application can be approved by the appropriate local body. Although it is not codified in the language of section 66427.5, the Legislature recorded its intent that by enacting section 66427.5 it was acting “to ensure that conversions ... are bona fide resident conversions.” (Stats. 2002, ch. 1143, § 2.)

The County of Sonoma (County) enacted an ordinance with the professed aim of “implementing” the state conversion statutes. It imposed additional obligations upon a subdivider submitting a conversion application to those required by section 66427.5. The ordinance also imposed criteria that had to be satisfied by the subdivider before the application would be presumed bona fide and thus could be approved.

A mobilehome park operator brought suit to halt enforcement of the ordinance on the ground that it was preempted by section 66427.5. The…