HVAC Permit Requirements in Northern Colorado

By the team at Homegrown Heating and Air Conditioning.

HVAC permit requirements in Colorado are not set by the state. They are set by the town, city or county that covers your address, which is why two bids on the same furnace can treat the paperwork completely differently.

That gap matters before you choose a contractor. We at Homegrown Heating and Air Conditioning pull permits across ten Northern Colorado jurisdictions, and the rules differ inside a twenty mile radius.

There Is No Colorado State HVAC License

Start here, because the confusion downstream comes from it. Colorado does not issue an HVAC or mechanical contractor license at the state level.

The Colorado Division of Professions and Occupations publishes the full list of regulated occupational professions in the state: accountancy, architects and engineers, barbering and cosmetology, combative sports, electrical, landscape architects, tissue banks, outfitters, passenger tramways, plumbing and radon professionals.

HVAC, mechanical and refrigeration are not on it, under that name or any other.

Two things follow. A company advertising a “Colorado state HVAC license” is describing something that does not exist. And the license that matters is the one issued by the jurisdiction your house sits in, which is checkable by phone.

Three state and federal credentials do apply to this trade: a Colorado electrical license for line voltage work, a Colorado plumbing license for plumbing, and federal EPA Section 608 certification for anyone handling refrigerant, and a contractor should be able to name which ones they hold. Homegrown Heating and Air Conditioning is licensed and insured throughout Northern Colorado.

HVAC Licensing in Colorado Changes Town to Town

The local picture:

Jurisdiction	Contractor licensing for mechanical work
Fort Collins	HVAC(RR) license for repair and replacement, a separate class from HVAC(R) and HVAC(C), plus a City business license
Larimer County, covering Laporte	Mechanical license, required in unincorporated areas since September 1, 2009
Greeley	Master Heating, Air Conditioning and Gas Pipe Fitting certification, plus a citywide contractor license from January 1, 2027
Loveland	Standard Master Mechanical license
Berthoud	Trade contractor license in the mechanical trade
Estes Park	Mechanical trade license, plus a Town business license first
Timnath	Town contractor license, with mechanical as a selectable type
Johnstown	Town contractor license, required before applying for a permit
Wellington	Town contractor license for contractors and subcontractors
Windsor	No Town contractor license required at all
Unincorporated Weld County	No County licensing or registration for mechanical contractors

Windsor surprises people. The Town states plainly that no contractor license is required for work within the Town, while still requiring state licenses for electrical and plumbing. There the license question gives you no filter, so ask about insurance, permits and references instead.

What to Ask Before You Sign

Four questions.

• Which jurisdiction is my address in, and what license do you hold there? “We are state licensed” is the wrong answer.
• Who pulls the permit, and will you give me the permit number? A bid that is lower because no permit is in it is a different scope, not a better price.
• Who meets the inspector? Someone has to be there with the manufacturer’s installation instructions on the job.
• Is the equipment sized with a load calculation? Several jurisdictions here require Manual J and Manual S work, and some ask for the documents at application.

Which Jobs Need an HVAC Permit in Colorado

The general rule holds everywhere here: installing, replacing or altering a mechanical or fuel gas system requires a permit. What differs is how specific each town gets.

Fort Collins publishes the clearest list. Its mechanical permit covers heating, cooling, ductwork, exhaust, mini splits, heat pumps, air handlers, rooftop unit replacement, air conditioning and furnaces, at $65 per heating appliance, with water heaters on a separate permit. A gas line for a heater also requires one.

Larimer County names air conditioning, boilers, furnaces, unit heaters, gas lines, water heaters, woodstoves and fireplaces on its miscellaneous permit list, which governs Laporte and every unincorporated address.

Johnstown, Wellington, Berthoud and Estes Park each name furnaces, air conditioners and water heaters. Greeley and Windsor publish no appliance list. Johnstown is useful for what it exempts: a new thermostat, a light fixture swap, and a fan replacement with no wiring changes.

Two jobs sit in a gap. Heat pumps and ductwork alterations are named only in Fort Collins and, as heat systems generally, in Larimer County. Whole-home humidifiers are named nowhere, in either column. We confirm those with the building department for the address rather than guess.

A Laporte Job and a Fort Collins Job Can Be on Different Codes

Code editions are adopted locally too, and they do not move in step.

Jurisdiction	Adopted I-code edition for mechanical work
Fort Collins	2024, applied to permits submitted on or after April 1, 2026
Larimer County	2024, effective January 1, 2026, with the 2021 codes repealed
Greeley	2021, effective January 1, 2023
Windsor	2024, effective January 1, 2026
Johnstown	2024, by Ordinance No. 2025-280
Wellington	2024, effective January 1, 2026
Berthoud	2024
Estes Park	2021, effective January 1, 2024
Loveland and Timnath	Unresolved in published sources; we confirm with the building department

Read the first two rows together. In early 2026, a job in Laporte and a job in Fort Collins in the same week were reviewed under different code editions, because the County repealed its 2021 codes on January 1 while the City applied its 2024 codes only to permits submitted from April 1. Same trade, minutes apart, different rulebook.

That is why a method that passed one inspection does not automatically pass the next, and why we confirm the address before specifying equipment on a heat pump installation or anything else.

What a Customer Said About How We Show Up

Rebecca Gibbs did not write about permits. Her review covers a service visit and the basics that decide whether a job goes well: the appointment held, and the technician explained the work.

“Excellent communication, tech was on time, friendly, informative and knowledgeable.”

We include it on purpose. Permits and inspections are administrative work, and the company that handles them is usually the one that turns up when it said it would. Read more customer reviews from Northern Colorado homeowners.

Ask Us Which Rules Apply to Your Address

Tell us where the house is and we will tell you which building department covers it, what has to be inspected and what the code edition asks for. We are licensed and insured, and we work seven days a week, 7 a.m. to 7 p.m. Contact Homegrown Heating and Air Conditioning to start.

Frequently Asked Questions

Do I need a permit to replace a furnace in Northern Colorado?

Yes, in every jurisdiction we serve. Fort Collins names furnaces on its mechanical permit at $65 per heating appliance, and Larimer County names furnace installation and replacement on its miscellaneous permit list. Johnstown, Wellington, Berthoud and Estes Park name furnaces too, and Greeley and Windsor cover them under the general rule.

Can I look up a contractor’s Colorado HVAC license?

Not at the state level, because the state does not issue one. The Division of Professions and Occupations regulates electrical and plumbing, not HVAC or mechanical. To verify a mechanical license you call the jurisdiction: the City of Fort Collins, the Larimer County Building Division, or your town office.

Does every Northern Colorado town require a licensed HVAC contractor?

No. Windsor requires no Town contractor license for this work, and unincorporated Weld County does not license mechanical contractors either. Fort Collins, Larimer County, Greeley, Loveland, Berthoud, Estes Park, Timnath, Johnstown and Wellington all do, though the class differs.

Does replacing my gas furnace mean I need new carbon monoxide alarms?

Usually yes. Colorado law ties an operational carbon monoxide alarm within 15 feet of the entrance to each sleeping room to a permit for a fuel-fired appliance replacement. Fort Collins, Johnstown, Berthoud and Estes Park each add stricter placement rules on top.

Do I pull a Fort Collins permit for a house in Laporte?

No. Laporte is unincorporated, so mechanical permits and inspections go through Larimer County rather than the City. The code edition, the sizing limits and the inspection calendar are the County’s, and two County inspection areas are not inspected every day.

Is a permit required for a whole-home humidifier?

We do not publish a yes or a no on that, because no jurisdiction on our list names humidifiers in either its permit-required or its permit-exempt list. We confirm with the building department for your address before scheduling the work.