Desmond

William and Tanya Desmond appeal from a judgment denying their petition for writ of administrative mandate. That petition sought to set aside the decision of the Board of Supervisors (Board) of the County of Contra Costa (County) denying their application for a land use permit. Appellants contend that the administrative findings of the Board are not supported by substantial evidence, and that the standards imposed by the applicable County ordinances exceed the maximum standards set by Government Code section 65852.2 for second units in residential zones. We disagree and therefore affirm the judgment.

I. Factual And Procedural Background

The subject property, which is located at 8 Golden Hill Court in Walnut Creek, is zoned R-15, single-family residential district. Appellants sought and received issuance of a building permit to construct an addition to their single-family home. The addition consisted of a new two-car garage and second-level bedroom addition with a separate foundation detached from the principal structure. The new unit was attached to the existing single-family home by means of second-story decking. The building permit contained a provision that no…