California Code, Government Code - GOV § 65973

(a) “Conditions of overcrowding” means that the total enrollment of a school, including enrollment from proposed development, exceeds the capacity of the school as determined by the governing body of the district.

(b) “Reasonable methods for mitigating conditions of overcrowding” includes, but is not limited to, agreements between a subdivider or builder and the affected school district whereby temporary-use buildings will be leased to the school district or temporary-use buildings owned by the school district will be used and agreements between the affected school district and other school districts whereby the affected school district agrees to lease or purchase surplus or underutilized school facilities from other school districts.

(c) “Residential development” means a project containing residential dwellings, including mobilehomes, of one or more units or a subdivision of land for the purpose of constructing one or more residential dwelling units.