What is an HVAC permit, and why does it matter?
A mechanical (HVAC) permit is your local jurisdiction's authorization to install or replace heating/cooling equipment, followed by an inspection confirming the work meets the adopted code. It protects you: it verifies safe gas, electrical, and venting connections, creates a record for resale and insurance, and keeps the work accountable to a third party — the Authority Having Jurisdiction (AHJ).
When does HVAC work need a permit?
As a rule, replacing or installing equipment needs a permit; routine repairs and maintenance generally do not. In the St. Louis metro, requirements vary by jurisdiction (the City of St. Louis, St. Louis County municipalities, St. Charles County, and Jefferson County each have their own building/mechanical divisions).
- Furnace, AC, or heat-pump changeouts — typically permitted
- New ductwork, gas line, or electrical for HVAC — typically permitted
- Like-for-like component repairs (capacitor, motor) — typically not
- Exact triggers, fees, and timelines vary by municipality — confirm with your local building department, or let us pull the permit for your jurisdiction
Jurisdiction specifics (St. Louis area)
Rules, fees, and inspection steps differ by AHJ. The principle is the same everywhere — pull the permit, install to the adopted mechanical code, pass inspection — but the details vary. Always confirm specifics with your local building department.
- City of St. Louis — an independent city with its own building department; it sets its own mechanical-permit requirements, fees, and inspection timelines, and we pull the permit for work here
- St. Louis County and its municipalities — the county and each incorporated municipality can have its own permit requirements and fees, so the exact process depends on your address; we confirm and pull the correct permit
- Jefferson County — administers its own building and mechanical permits and inspections; we handle the permit for your job
- St. Charles County — the county and its cities set their own permit requirements, fees, and timelines; we pull the required permit for your location
What happens if work isn't permitted or up to code?
Unpermitted equipment can fail inspection later, complicate or reduce a home sale, create insurance problems after a loss, and — most importantly — hide unsafe gas or electrical work. Correcting unpermitted work after the fact usually costs more than doing it right the first time.
How Degenhardt handles permits for you
When your job requires a permit, we handle the process and the inspection so it's done correctly and on record — a differentiator from installers who skip it. Our Local 36 union training and NATE certification mean the work is built to pass.
Proof: a licensed, family-owned contractor serving the St. Louis metro since 1984 — we pull the required permits and manage inspections as part of the job, with NATE-certified, Sheet Metal Workers' Local 36 union-trained technicians.
Note: This page is educational, not legal advice. Codes, fees, and permit requirements change and vary by jurisdiction — always confirm specifics with your local building department (the Authority Having Jurisdiction) before starting work.
Frequently asked questions
In most St. Louis-area jurisdictions, equipment changeouts require a mechanical permit and inspection; routine repairs usually don't. Confirm specifics with your local building department — we handle the permit when your job needs one. This is educational guidance, not legal advice.
A licensed contractor typically pulls the permit as part of the job. Be cautious if a company asks you to pull an 'owner' permit for work they're doing — it can shift liability to you. Practices vary by municipality, so confirm with your local building department; on the jobs we install, we pull the permit for you.
It can. Buyers, inspectors, and appraisers may flag unpermitted equipment, which can delay a sale or force corrective work. Permitted, inspected installs create a clean record.