Caldwell, ID Building Safety: Fire Sprinkler Requirements (2026)

When Caldwell adopted the 2018 International Residential Code with local amendments at § 12-01-21, it made a deliberate choice on residential fire sprinklers. The amendment deletes IRC section R313.2, "One- and two-family dwellings automatic fire sprinkler systems," in its entirety, meaning the model code's mandate for sprinklers in new single-family and duplex construction does not apply inside Caldwell. For townhouses, the city did not delete the sprinkler section outright but rewrote the exception under IRC section R313.1: instead of requiring an automatic residential fire sprinkler system, a townhouse project can satisfy the rule by installing either two separate one-hour fire-resistance-rated walls, or a single common two-hour fire-resistance-rated wall as described in section R302.2.2, between dwelling units.

That same substituted exception also covers additions or alterations made to an existing townhouse that never had a sprinkler system installed, so a remodel does not retroactively trigger a sprinkler retrofit. The amendment package sits alongside other fire-and-life-safety edits in the same section, including a rewritten garage-to-house fire separation rule requiring 5/8-inch type X gypsum board and solid or 20-minute fire-rated doors between an attached garage and the residence, and a deleted floor fire-protection rule under R302.13. Builders should read § 12-01-21 as a whole rather than assuming any single IRC fire provision applies unmodified, since the city has revised or removed several of them.