Building Safety in Contra Costa County, CA (2026)

5 county-level rules, plus city-specific rules for 9 cities in Contra Costa County, California.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Contra Costa County. If you live within an incorporated city, that city's own rules apply — see the city list below.

Smoke Alarms

California Health & Safety Code 13113.7 and the California Residential Code require working smoke alarms in all dwelling units in Contra Costa County. Alarms are required in each sleeping room, outside each sleeping area, and on every level including basements. Alarms manufactured after 2015 must have a 10-year sealed battery.

Building Safety: Smoke Alarms

Heavy Restrictions

California Health & Safety Code § 13113.7(a)-(b), (e)

(a) (1) Except as otherwise provided in this section, smoke alarms, approved and listed by the State Fire Marshal pursuant to Section 13114 at the time of installation, shall be installed, in accordance with the manufacturer's instructions in each dwelling intended for human occupancy. (2) For all dwelling units intended for human occupancy for which a building permit is issued on or after Janu...

Full ordinance details →Official source ↗

Carbon Monoxide Detectors

California Health & Safety Code 13260-13263 (Carbon Monoxide Poisoning Prevention Act of 2010) requires CO alarms in all dwelling units with fossil-fuel appliances, fireplaces, or attached garages. Alarms must be installed outside each sleeping area and on every level of the home.

Building Safety: Co Detectors

Heavy Restrictions

Full ordinance details →Official source ↗

Electrical Permits

Electrical permits are required in unincorporated Contra Costa County for most work beyond minor repairs. The county Building Inspection Division enforces the California Electrical Code (Title 24 Part 3, based on NEC). Permit exemptions apply to simple like-for-like replacements and low-voltage work.

Building Safety: Electrical Permits

Heavy Restrictions

Full ordinance details →Official source ↗

Plumbing Permits

Plumbing permits are required in unincorporated Contra Costa County for new installations, alterations, water heater replacements, and sewer lateral work under the California Plumbing Code adopted in Title 7 of the County Ordinance Code. Permits are issued by the DCD Building Inspection Division.

Building Safety: Plumbing Permits

Some Restrictions

Full ordinance details →Official source ↗

Roofing Permits

Unincorporated Contra Costa County requires building permits for reroofing projects under the California Building Code as adopted in County Ordinance Code Title 7. Class A fire-rated roofing assemblies are required in WUI and VHFHSZ areas (Title 7, Chapter 74-6).