Portland, ME Building Safety: Fire Sprinkler Requirements (2026)

Chapter 10's Article I amendments to NFPA 101: Life Safety Code (2018 edition) carve out two accessory dwelling unit exceptions from the code's automatic sprinkler requirements, aimed at Portland's push for more ADUs without forcing costly retrofits. 1 to add: an automatic sprinkler system is not required for constructing an additional dwelling unit in an existing detached one-family dwelling, unless that construction would otherwise trigger the automatic sprinkler requirements of NFPA Chapter 43, as amended. 3 to add a parallel exemption for detached accessory structures: constructing a dwelling unit inside a detached accessory structure doesn't have to meet Chapter 24's sprinkler requirements so long as that accessory structure was built more than five years before the new dwelling unit was added, and the work doesn't otherwise trigger Chapter 43's sprinkler thresholds.

Outside these two carve-outs, Chapter 10 leaves the underlying NFPA 101 sprinkler mandates for other occupancy types intact, and § 10-3(e) separately lets the authority having jurisdiction, the fire chief or designee under § 10-2, modify water-supply requirements for individual sprinkler installations where meeting them is impractical, provided the reduced requirements stay no less stringent than Maine's statewide minimum sprinkler water-supply standards. Compliance with any sprinkler mandate that does apply is verified through the § 10-3(b) inspection power, and interfering with that inspection is a separate Article I violation.