Carbon monoxide detector soon to be required in rental units

Question: I recently bought a duplex. I need to complete repairs to the property in order to list the two units for rental. A friend recently told me that I have to install a carbon monoxide detector as well as a smoke detector if I rent out one of the units. Are these devices necessary?

Answer: The California law regarding the installation of carbon monoxide detectors is being gradually phased in.

Carbon monoxide detectors were required in all single-family dwellings as of July. For other properties, such as your duplex, the date is January 2013. This requirement applies to any dwelling that has a fossil-fuel-burning heater, appliance or fireplace.

Smoke detectors have been required in multi-unit dwellings for a number of years. You should check local fire regulations, but in general there should be at least one smoke detector in each unit, and one in any common stairway, if your duplex has one. You have a right to enter the rental premises to inspect or repair either type of detector, as long as you give proper written notice 24 hours in advance and limit your entry to normal business hours. You cannot use your right to inspect the detectors as an excuse to conduct a general inspection of the unit, because non-governmental landlords have no right under California law to conduct general inspections.


Eichner is director of Housing Counseling Programs for Project Sentinel, a mediation service based in Sunnyvale, Calif. To submit a question, go to