Polk County, IA Building Safety: Carbon Monoxide Detectors (2026)

Polk County's Chapter 20 Mechanical Code adopts the International Mechanical Code (IMC) as amended by the Iowa Plumbing and Mechanical Systems Board, and the county added its own carbon monoxide trigger onto IMC Section 102.4, Additions, alterations or repairs. The added language is narrow and specific: it applies to 'existing dwelling units' and fires only 'when the heating and/or cooling equipment is replaced within,' so routine repairs or minor part swaps generally don't trigger it, but replacing a furnace, boiler, heat pump, or central air condenser does. Once triggered, the alarm has to be installed per IBC Section 915 or IRC Section R315, the same placement standards that already govern CO alarms in new construction and in the county's home day care rule under Appendix AM105.

This CO alarm requirement rides on the mechanical permit process the county already runs: a mechanical permit is required for the equipment replacement itself under Section 20.1.2, work exempt from that permit is limited to the short list in Section 20.1.11, covering things like minor repairs, portable heating or cooling equipment, and small self-contained refrigeration units, and the Polk County Building Services Department, named as the enforcement agency for the Mechanical Code at item .3, inspects the installation. A contractor or homeowner who replaces heating or cooling equipment without pulling the required permit, or without the alarm the amendment calls for, is subject to the same violation and stop-work provisions that apply to the rest of Chapter 20.