Longmont, CO Building Safety: Carbon Monoxide Detectors (2026)

Longmont's carbon monoxide rule sits inside Chapter 16.20, the city's adoption of the 2021 International Property Maintenance Code under Ordinance No. O-2021-65, effective November 30, 2021. Section 16.20.380 rewrites the model code's Section 705.1 in full. The rewritten text requires carbon monoxide detection in every residential occupancy that has a fuel-fired appliance, a fireplace, or an attached garage, once that unit has been offered for sale, changed ownership, or had interior alterations, repairs, a fuel-fired appliance replacement, or an addition that required a permit, on or after July 1, 2009. Beyond that triggering-event language, the section separately requires carbon monoxide detection in every dwelling unit with a fuel-fired appliance, fireplace, or attached garage.

Placement is specific: detectors must be installed within 15 feet of any sleeping area, and may be battery powered, hard-wired, or cord-and-plug type. Where a fuel-burning appliance sits inside a bedroom or its attached bathroom, the code requires a carbon monoxide alarm inside the bedroom itself, not just nearby.

Enforcement rides on the same chapter's general violations provisions at Section 16.20.080. Failing to install a required detector is a code violation under Section 109.1, and each day it continues counts as a separate offense punishable under Title 1, Chapter 1.12: up to a $500.00 fine and 90 days in jail, or both. The city can also treat an ongoing violation as a public nuisance and pursue injunctive relief in court, and if the city corrects it directly, the cost plus a 20 percent administrative charge becomes a lien on the property after the 14-day notice-and-objection process, with appeal rights running to the master board of appeals under Chapter 16.30.