Cal. Health & Safety Code § 50664

Deferred-payment loans may be made to local agencies for repair of substandard dwellings through a master agreement and fund commitment. Such agreements shall limit the amount of deferred-payment rehabilitation loans to actual rehabilitation costs to the local agency, shall require that the full amount of rehabilitation costs be made a special assessment against the property involved, and shall require that the full amount collected, including any interest attributable to delinquency, be promptly repaid to the Housing Rehabilitation Loan Fund. However, loans made pursuant to this section shall not otherwise bear any interest.