What happens if you skip the permit (and you needed one)
- Stop-work order triggers $500–$1,000 daily fines in Westminster until you halt construction and pull a retroactive permit, which costs double the original fee.
- Insurance denial: your homeowner's policy excludes unpermitted structures, and a lender's title company will flag an unpermitted ADU during refinance or sale, costing $15,000–$40,000 in forced removal or legal remediation.
- Code enforcement complaint from a neighbor results in a notice of violation; Westminster will order removal within 30 days or impose liens up to $5,000 plus demolition costs ($8,000–$15,000).
- Transfer Disclosure Statement (TDS) requirement in California law: you must disclose the unpermitted ADU to buyers, killing deals or forcing $20,000–$50,000 price cuts.
Westminster ADU permits — the key details
California Government Code 65852.2 (amended by SB 9, AB 68, AB 881) mandates that Westminster allow at least one detached ADU and one junior ADU on any single-family lot, regardless of lot size, and allows above-garage ADUs in some cases. The state law does not allow the city to require owner-occupancy, does not allow setback requirements stricter than 4 feet (or the lesser of 25% of lot depth for detached ADUs), and prohibits parking requirements in certain zones (particularly transit-rich areas, though Westminster is not consistently transit-rich). However, Westminster's Building Department still requires a full building permit for all ADUs, and the city does enforce design review, utility capacity verification, and Environmental Review (CEQA) if the ADU triggers cumulative impacts. The city's current ADU ordinance aligns with AB 68 and AB 881, but the Building Department interprets setback and utility requirements narrowly — meaning you may need a surveyor's letter and a utility capacity study even though state law says the city cannot use these as a basis for denial if you comply with baseline standards. This is where Westminster differs from larger coastal cities like San Diego, which have pre-approved ADU plan libraries and online fast-track systems; Westminster does not, so you must submit custom plans and expect a full 60-90 day review cycle.
Contact city hall, Westminster, CA
Phone: Search 'Westminster CA building permit phone' to confirm
Typical: Mon-Fri 8 AM - 5 PM (verify locally)