CodeMandatory
One- and two-family dwellings 3+ stories above grade require automatic sprinklers
2025 RCNYS §R309.2 One- and two-family sprinklersDescription
Single-family + duplex dwellings with three or more stories above grade plane must be sprinklered per P2904 or NFPA 13D. Manufactured homes and additions to existing un-sprinklered buildings are exempt.
Why this exists
Most modern walk-out basement / 2-story / habitable-attic homes can hit three above-grade stories depending on how the basement is classified. The architect must determine story count early — if you're going to be at three stories, the sprinkler system is non-negotiable.
Categories
Life safetyStructure
Applies to
- Jurisdiction: New York State
Source
NY Dept of State / ICCno manifest entry
2025 Residential Code of New York State (2025)
Section: R309.2 One- and two-family sprinklers
Published 2025-07-01 · last verified 2026-05-15
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Garage / dwelling fire separation · IRC R302.6
- Habitable space minimum ceiling height · IRC R305.1
- Egress window net opening dimensions · IRC R310.2
- Stair riser, tread, and headroom · IRC R311.7
- Smoke alarms required throughout dwelling · IRC R314
Last reviewed 2026-05-15.