Mono County, CA Fire Regulations: Smoke Detectors (2026)

Smoke and carbon monoxide alarm rules in unincorporated Mono County are set by California statewide law rather than a distinct county ordinance. Under California Health & Safety Code section 13113.8, every single-family dwelling and factory-built home that is sold must have an operable smoke alarm approved and listed by the State Fire Marshal, installed per the Marshal's regulations. The California Building Standards Code (Residential Code) requires smoke alarms in each bedroom, outside each sleeping area, and on every level of a dwelling, and modern installations must be interconnected and hard-wired with battery backup in new construction. For carbon monoxide, Health & Safety Code section 17926 requires the owner of any dwelling unit intended for human occupancy to install a State Fire Marshal-approved carbon monoxide device in each existing unit that has a fossil-fuel-burning heater or appliance, a fireplace, or an attached garage; the deadline for existing single-family homes was July 1, 2011, and January 1, 2013 for other existing dwellings. In rental units, landlords are responsible for installing the required detectors and ensuring they work at the start of each tenancy. These statewide requirements apply throughout Mono County. New construction and remodels in the unincorporated county are reviewed against the current California Building Standards Code by Mono County Building & Safety.