Cal. Ed. Code § 17372
No school building examined and found to be unsafe for school use pursuant to Section 17367 and not repaired or reconstructed in accordance with the provisions of this article, and no school building which has never met the requirements of Article 3 (commencing with Section 17280) of this chapter, shall be used as a school building for elementary or secondary school purposes after June 30, 1975, unless the governing board of the school district has requested and obtained from the State Allocation Board authority for use of the building for a specific period beyond that date. Prior to requesting this authority, the governing board shall adopt a resolution declaring the board's intention to utilize the building as a school building after June 30, 1975, pending its repair, reconstruction, or replacement. The State Allocation Board shall not authorize any school district to use a building beyond June 30, 1975, unless it has first determined that the school district has already proceeded with a plan of total repair, reconstruction, or replacement in a timely manner and a contract has been let for any phase of, and work commenced on, the project. In no event shall the State Allocation Board authorize the use of any unsafe facilities for a period extending beyond the completion of the replacement facilities or beyond June 30, 1977, whichever occurs first.
For purposes of this section, "school building" does not include any portable building. Portable buildings may be used beyond June 30, 1975 to meet temporary housing needs until all repair, reconstruction or replacement of all district school buildings is complete or until June 30, 1977, whichever occurs first, provided that the governing board of the district has requested and obtained from the State Allocation Board authority for use of such portable buildings. The State Allocation Board may grant this authority only to those districts in which 20 percent or more of the schools are subject to partial or complete reconstruction pursuant to Section 17367. Any portable buildings for which authority is granted for temporary use pursuant to this section shall not be subject to Article 3 (commencing with Section 17280) or Article 6 (commencing with Section 17365) of this chapter during the period of the authorized use.
Ca. Educ. Code § 17372