Brentwood, CA Rental Property Rules: Mold Disclosure (2026)

Mold disclosure in Brentwood rentals is governed by California Civil Code sections 1941.7 and 26147 (the Toxic Mold Protection Act of 2001) and Health and Safety Code section 17920.3, which lists visible mold growth as a substandard condition. Landlords must provide written disclosure of any known mold that affects the habitability of the unit, and they must remediate leaks and moisture intrusion that create mold-favorable conditions. Although California never adopted formal permissible exposure limits for mold spores, Health and Safety Code section 17920.3(a)(13) allows code enforcement to cite any "visible mold growth" except for small amounts on non-porous surfaces. Brentwood's Neighborhood Improvement Services Division investigates complaints through the Municipal Code Chapter 8.12 nuisance and property maintenance provisions. Tenants should first notify the landlord in writing, give a reasonable period (typically 30 days) to repair, and then may file a complaint with the city or withhold rent under Civil Code 1942 if repairs are not made. Contra Costa County Environmental Health handles cross-referrals involving severe cases. Landlords who fail to disclose or repair known mold face civil liability for rent rebates, relocation costs, and medical damages, and insurance carriers often exclude mold claims so prevention is the landlord's responsibility.