Fort Collins, CO Building Safety: Fire Sprinkler Requirements (2026)
Key Facts
- Requirement
- Automatic sprinkler system in two-family dwellings
- Exception
- Additions/alterations to unsprinklered existing buildings
- Adopting ordinance
- City Code Sec. 5-30
- Code section
- 2024 IRC Sec. R309.2
- Enforcing agency
- CDNS building permit review
Summary
Fort Collins requires an automatic residential fire sprinkler system in every new two-family dwelling, going beyond the model code's one-and-two-family standard, though additions or alterations to an unsprinklered existing building are excused.
23.Section R309.2 One- and two-family dwellings automatic sprinkler systems is amended to read as follows: R309.2 Two-family dwellings automatic fire sprinkler systems. An automatic residential fire sprinkler system shall be installed in two-family dwellings. Exception: An automatic sprinkler system shall not be required for additions or alterations to existing buildings that are not already provided with a sprinkler system.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 155 | Transitional Land Use Code (for project before May 17, 2024): Supplement 61 | Traffic Code: Supplement 27).
Full Breakdown
City Code Sec. 2, retitled Two-family dwellings automatic fire sprinkler systems, to state flatly that an automatic residential fire sprinkler system shall be installed in two-family dwellings. This local amendment narrows the model code's broader one- and two-family sprinkler section down to a mandate specifically for duplexes and other two-family structures built in Fort Collins, meaning any new duplex permit application must include a fire sprinkler system as designed and installed to the applicable NFPA 13D standard referenced elsewhere in the residential code. The amendment carries one built-in exception: an automatic sprinkler system is not required for additions or alterations to existing buildings that were not already provided with a sprinkler system, so a homeowner adding a room to an existing, unsprinklered duplex does not trigger a retrofit obligation.
The requirement is administered through the standard building permit and plan review process handled by CDNS; sprinkler plans for a two-family dwelling are reviewed alongside the rest of the residential permit set, and the Poudre Fire Authority, which serves Fort Collins, is typically consulted on fire-protection system design and final inspection sign-off before occupancy.
Violations & Fines
Constructing or occupying a new two-family dwelling without the required sprinkler system is a building code violation enforced by CDNS; the Building Official can withhold the certificate of occupancy until the sprinkler system is installed and inspected, and an unpermitted duplex found without required fire protection can be ordered to retrofit before continued occupancy is authorized.
Frequently Asked Questions
Does Fort Collins require sprinklers in a new duplex?
Do I need to add sprinklers if I remodel an existing duplex without them?
Does the sprinkler rule apply to single-family homes in Fort Collins?
Sources & Official References
Other rules in Fort Collins
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Fire Sprinkler Requirements in Nearby Cities
How other cities in Larimer County handle fire sprinkler requirements.