Sprinkler retrofits and ADU rules in Temecula and Murrieta

Large lots make the Temecula Valley ADU country, and the sprinkler question follows every one. State law answers it: under Government Code section 66314, an ADU shall not be required to have fire sprinklers if they are not required for the primary residence, and building an ADU shall not trigger sprinklers in the existing primary dwelling. A pre 2011 house with no sprinklers can usually add a detached unit without them. A sprinklered tract house usually means the ADU gets them.

Remodels and additions are decided locally. Temecula, Murrieta and Riverside County each set what triggers the sprinkler requirement, and the numbers are not the same. We will not print a threshold we cannot cite. Ask the building department for your lot in writing.

For a retrofit that is required or simply wanted, cost follows access. A remodel with open ceilings is the moment to do it. On a well lot, a retrofit may also mean adding the tank and pump the house never had.

Ranges and their sources are on the ADU page, and the area overview is on the Temecula and Murrieta page.