Homeowner guide
Carbon monoxide alarms: Colorado rules
General info only. Check with a licensed pro and your local building department.
If in doubt, stop and call a licensed professional.
When Colorado law requires a CO alarm, and where it goes.
What the sources say
| Topic | What the source says | Source |
|---|---|---|
| Selling a home | C.R.S. 38-45-102(1): the seller of an existing single-family home with a fuel-fired heater or appliance, a fireplace, or an attached garage must make sure an operational CO alarm is installed within 15 feet of the entrance to each room used for sleeping (or where the building code says). | Source page checked 2026-11-02 |
| Remodeling | C.R.S. 38-45-102(2): in homes with fuel-fired appliances or an attached garage, permitted interior alterations, repairs, fuel-fired appliance replacements, additions, or added bedrooms trigger the same CO alarm requirement. | Source page checked 2026-11-02 |
| Rentals | C.R.S. 38-45-104: rental units are covered; at a change of tenant the landlord supplies batteries and replaces missing alarms. | Source page checked 2026-11-02 |
| Don't disable | C.R.S. 38-45-102(3): no one may remove batteries or disable a CO alarm except to inspect, maintain or replace it. | Source page checked 2026-11-02 |
Not confirmed yet
- Unknown Colorado fire safety office (DFPC) homeowner CO guide — PDF did not load for our tools; not reviewed.
- Unknown Extra rules in your city's adopted building code — ask your building office.
Checked 2026-11-02. General information, not legal advice. Rules change — confirm with the source. Report an error.