The owners contended that the applying for permit(s) to construct seriatim of one to five home would be economically infeasible and that the city intended to convert their land into open space by preventing its development.

The California Supreme Court refused to recognize the existence of a regulatory taking cause of action, and held that the only remedy available to the owner would be a petition for a writ of mandate seeking to invalidate the regulation on grounds of denial of substantive due process.

However, as noted, because the owners had not yet applied for a permit for development, the court found that the issue of whether an as-applied taking occurred, was not yet ripe for decision.

The Court held that a general zoning law can be a taking if the ordinance does not substantially advance a legitimate state interest or denies an owner economically viable use of his land.

Gideon Kanner and Michael M Berger, The Nasty, Brutish and Short Life of Agins v. City of Tiburon, 50 Urban Lawyer 1 (2020)