Thornton Council adopts 2024 building and 2024 fire codes with local amendments, effective July 1

Thornton City Council on May 13 approved an ordinance adopting the 2024 editions of the International Building Code family and the 2024 International Fire Code, and the 2023 edition of the National Electrical Code, with local amendments. The ordinance takes effect July 1, 2025; building permit applications submitted before that date may be completed under the 2021 codes.

City staff and fire officials told the council the update aligns Thornton with surrounding jurisdictions and state requirements. Justin Nielsen, plans examining supervisor, said the state requires adoption of the 2024 International Energy Conservation Code (IECC) and the state-developed electric-ready and solar-ready rules. Those state requirements add minimum provisions for panel capacity, pre‑wiring for solar and electric appliances, and provisions for EV charging in single‑family residential construction and designated EV charging spaces in commercial and multi‑unit residential projects.

Nielsen described other code changes carried in the 2024 cycle, including clarified definitions for assumed lot lines on a single lot with multiple buildings, and a staff effort to remove some previously carried-forward local amendments to align more closely with the core International Codes while retaining a few business‑friendly local amendments. Staff also added a code‑violation process that names the property owner as the liable party and a provision to have the city automatically adopt the National Electrical Code concurrent with the State’s adoption cycle.

Dan Biro, deputy fire marshal, outlined three new local fire‑code amendments the department recommends: (1) an emergency responder radio coverage provision for existing buildings that would require owners to test in‑building radio signal strength and install radio amplification systems if signals fail to meet minimum levels; (2) an operational permit framework for valet‑trash services in multifamily buildings, with permitting conditions and revocation for noncompliance; and (3) a requirement that residential secondary kitchens (for example, a basement kitchen) be protected by a residential hood suppression system to reduce cooking‑related fires.

The council opened the item for public comment during the required public hearing. Resident Dariush Namazi spoke and expressed frustration with how the public comment period was handled for the hearing and said he felt the hearing process squeezed speakers; he did not state a specific technical objection to the code changes. Greg Gill asked about the correct protocol to submit recommendations and letters to the city; staff told him the meeting’s public comment portion was reserved for the hearing and invited him to submit written materials to staff outside the hearing.

Council member Ayala read the ordinance on second reading and moved for approval; a second was recorded, and the motion passed unanimously on roll call. The ordinance includes local amendments described above and sets July 1, 2025 as the effective date; permits applied for before that date may be finished under the 2021 codes.

What changed and why it matters: the 2024 I‑codes and 2024 fire code include updated safety, energy and construction standards; the state’s electric‑ready and solar‑ready requirements are intended to reduce future retrofit costs and to help accommodate rooftop solar and EV charging. The fire department’s radio coverage amendment addresses firefighter safety and communications inside buildings; the valet‑trash permit and secondary‑kitchen hood requirements address operational and fire‑risk issues in multifamily and altered residential occupancies.

Implementation and next steps: staff said applications filed before July 1 may be finished under 2021 codes; applications filed on or after July 1 must comply with the 2024 I‑codes, the 2024 IFC and the 2023 NEC as adopted. Council and staff noted they will continue outreach to the building and development community on the changes and local amendments.