Colorado HVAC permit requirements

Colorado does not run a state building department for houses. The state writes minimum energy standards and tells each county and municipality that has a building code to enforce them. The county building-code statute only says that a county ‘is authorized to adopt ordinances and a building code’.

So Denver, Colorado Springs, Boulder and every county each decide their own code edition, mechanical permit and submittal. This page covers only what the state sets.

A county that has a building code must also have an energy code: ‘Every board of county commissioners that has adopted and enforced one or more building codes, or that adopts and enforces one or more building codes after July 1, 2022, shall adopt and enforce an energy code that applies to the construction of, and major renovations and additions to, all commercial and residential buildings’. The statute’s definition of a building code includes ‘mechanical systems’.

The edition floor depends on when the county updates its codes. For updates on or after July 1, 2023 and before July 1, 2026, the county ‘shall adopt and enforce an energy code that achieves equivalent or better energy performance than the 2021 international energy conservation code and the model electric ready and solar ready code language’. For updates on or after July 1, 2026, the benchmark becomes ‘the model low energy and carbon code developed for adoption by the energy code board’.

Cities and towns get a parallel statute: ‘The governing body of any municipality that has adopted and enforced one or more building codes’ ‘shall adopt and enforce an energy code’. The same two timing windows apply.

Local changes may only add stringency: ‘so long as the amendments do not decrease the effectiveness of the energy code’. A rural county that applies for a state training grant and is not awarded one may instead follow ‘one of the last three most recent editions of the international energy conservation code’.

The Colorado Energy Office announced that ‘the Colorado Energy Code Board has published its Model Low Energy and Carbon Code.’ On timing: ‘becomes Colorado’s new minimum energy code on July 1, 2026.’ On who it binds: ‘Any municipality or county that updates any of its building codes after that date must adopt the model code, or a code that will achieve greater energy efficiency and pollution reductions.’

On edition: ‘The code is based on a modified version of the 2024 version of the International Energy Conservation (IECC) Code, updating the state requirement from the previous 2021 version.’

The statute directing the Energy Code Board says the model code must ‘Allow projects consisting of only replacing a space or water heating system, at the end of that system’s useful life, with the installation of a new system using the same fuel or power source, without triggering pre-wire requirements’.

That concerns pre-wire (electric-ready) requirements. It does not say a replacement needs no permit or no load calculation. We found no state rule on changeout permits.

The State Plumbing Board writes the state plumbing code. It is defined as ‘a code established by the board that consists of standards for plumbing installation, plumbing materials, conservation, medical gas, sanitary drainage systems, and solar plumbing that could directly affect the potable water supply’, and local governments may amend it ‘as long as the amendments are at least equal to the minimum requirements set forth in the Colorado plumbing code’.

In a conflict with the 2021 or 2024 IECC or a local energy code, ‘the Colorado plumbing code prevails’.

Varies — not set by a Colorado state statute we read. None of the sections quoted here writes “Manual J” or “Manual S”. We could not retrieve the equipment-sizing text of the Colorado Model Low Energy and Carbon Code (the publisher’s online edition returned only a page shell), so that is Not verified.

Local practice differs. One county’s own 2016 handout, which may not be current, told builders: ‘An ACCA Manual J 8th report shall be submitted with plans for new residences with a furnace.’ That is one county, not the state.

Not verified. No state statute or Energy Office page we read names Manual D. Duct rules come from the code edition a county or city enforces.

Not verified. We found no state statute creating an HVAC contractor license, but we did not locate an official page saying so outright, so we report it as unconfirmed. Plumbers are licensed by the state.

Two items in the official record do not line up. First, the Energy Office’s page says in its summary ‘State law requires local jurisdictions to adopt and enforce the Colorado Model Low Energy and Carbon Code upon updating any other building code.’ and in its technical-assistance paragraph still says ‘Jurisdictions must also adopt the 2021 IECC, the Colorado Model Electric Ready and Solar Ready Code, and other advanced energy code amendments.’ The statute’s two windows explain the difference, but the page is not fully updated.

Second, C.R.S. § 24-38.5-402 is sometimes cited as the energy code mandate. It is not. Its full text is: ‘Before July 1, 2024, the Colorado energy office shall identify model green code language for adoption. The Colorado energy office shall promote the voluntary adoption of this model green code language.’ The mandate sits in § 30-28-211 (counties) and § 31-15-602 (municipalities).

The state gives you the energy-code floor and the local building department gives you the answer: edition, amendments, load calculation, changeout permit. We have not yet researched any Colorado city or county in full. Statutes were read from a public mirror of the C.R.S. stating it was current through Fall 2025; confirm subsection numbers against the official text.