San Marcos, CA Building Safety: Fire Sprinkler Requirements (2026)

2, which sets baseline sprinkler triggers by occupancy and size, and expressly extends it to Group R-2 (apartments, condos, townhomes) and Group R-3 (single-family and duplex) occupancies that the base code would otherwise exempt. For new multi-family construction, San Marcos layers on three specific hardware requirements: a listed electric water-flow bell tied into the system, an exterior fire sprinkler head on every covered exterior balcony, and a permanently installed 300 psi pressure gauge at the riser so the Fire Department can verify system pressure at a glance.

3 exceeds what the site can supply, the Fire Code Official can require sprinklers throughout the entire building, not just the new portion. Beyond size triggers, the Fire Code Official has discretion to require sprinklers wherever no water main exists to deliver the needed fire flow, or wherever a special hazard is present; listed examples include poor access roads, steep grades, canyon rims, heavy brush, and a fire department response time longer than five minutes. That addition-triggered retrofit exception is capped at one use per three-year period measured from the date of the last approved permit, so a property cannot be forced through repeat full-building sprinkler retrofits for a series of small phased additions within the same three years.