The Saint Paul rule
DSI's handout When is a permit required? says: "Work on electrical, plumbing, piping, sheet metal or heating and air conditioning systems requires trade permits." For the most common job, DSI's furnace and AC page (read 23 October 2026) lists what an installation needs:
| Permit | What it covers | Inspection line (7:30 to 9:00 a.m. weekdays) |
|---|---|---|
| Electrical | The unit's circuit and disconnect | Electrical, 651-266-9003 |
| Warm Air / Ventilation / General Sheet Metal | The furnace, air handler and ducts | Warm Air, 651-266-9006 |
| Mechanical (gas burner, refrigeration) | The gas-fired appliance; refrigerant lines for AC | Mechanical, 651-266-9004 |
DSI defines a gas burner as "any natural gas fired heating device (e.g., furnace, boiler, space heater, or unit heater...)", which is why a gas furnace needs the mechanical permit as well as the sheet-metal one (Gas Burner). New gas piping is a plumbing and gas fitting permit; see Saint Paul plumbing permit.
The heat-loss rule
DSI's furnace requirements sheet applies the 2020 Minnesota Residential Energy Code: "Furnace replacements require whole house heat loss calculations." Equipment is sized to ACCA Manual S, and oversizing "shall not exceed 40 percent of the calculated load" for heating and 15 percent for cooling, at Saint Paul design temperatures of 88°F in summer and -15°F in winter. A forced-air furnace needs a programmable thermostat. So a quote that simply matches the old furnace's size has skipped a step the permit requires; ask the installer for the heat-loss calculation.
Who can pull it
DSI's warm air page sets the conditions for owners: you own the property, you legally homestead it with Ramsey County, and you do the work yourself. Duplex owners must live in the side where the work is done. The owner signs the homeowner's warm air and mechanical affidavit, which says it is "unlawful" to do this work as a homeowner on property "rented, leased or occupied by others".
Contractors need Saint Paul's own license. For residential buildings of three or more units, the permit must be obtained by a warm air/ventilation contractor licensed by the City of Saint Paul, and if you hire a licensed contractor, "they are responsible for obtaining the warm air/ventilation permit". The license requires a Saint Paul Master Warm Air or Ventilation Certificate of Competency (or a Minneapolis master's card), $500,000 liability insurance and the $25,000 state mechanical bond, and costs $188 a year (DSI license page, read 22 October 2026). Gas burner and refrigeration are separate City trade licenses (Mechanical).
What it costs, and what the City does not publish
The only HVAC-related fees we could read on DSI's pages are the electrical ones on the furnace page: $15 per unit installed per circuit, no charge when the unit is on a permit with other electrical work and no new circuit, an $85 minimum and a $1 minimum state surcharge. The warm air page links "Required fee" to the license page, which lists license fees, not permit fees, and the gas burner page gives none. PAULIE calculates the warm air and mechanical fees when you apply; ask DSI on 651-266-8989 for the amount before you file.
Inspections and deadlines
The electrical final is called "when the furnace and/or air conditioner is completely installed and ready for operation". Each trade has its own inspector, found on DSI's area maps. DSI's permit pages say a permit expires if work does not start within 180 days of issue or stops for 180 days. Look the permits up afterwards in PAULIE's Find Property Information (Saint Paul building permit search); one furnace job should show more than one permit.
What 14,174 Saint Paul HVAC permits show
| Measure | Saint Paul HVAC and gas |
|---|---|
| Permits on homes, October 2023 to September 2026 | 14,174 |
| Firms | 282 |
| Firms with a permit in the last 12 months | 183 |
| Finaled (permits a year or more old) | 55.5% |
| Usual days from issue to final | 164 |
| Usual filed value | $6,760 |
| Middle half of firms' usual value | $4,000 to $8,000 |
| 10th / 90th-percentile firm finished share (10+ permits) | 34.2% / 80.0% |
| Busiest / quietest month | October (136) / August (62) |
HVAC is the Saint Paul trade where open permits pile up: 79 of the 109 HVAC firms with 10 or more permits finaled under 70% of theirs, and the 10th-percentile firm finaled 34.2%. Filing peaks in October as heating season starts and is quietest in August. Prices by job size are on Saint Paul HVAC cost, and the trade-by-year counts on Saint Paul permit statistics.
See every Saint Paul HVAC contractor by permits finaled →
Before you hire
Ask for the Saint Paul warm air license and the DLI mechanical bond; the checks are in the Saint Paul contractor license lookup. 31.9% of Saint Paul HVAC firms had no DLI bond match by name in our file. Then compare finals on the Saint Paul HVAC list. Other cities' rules are in do I need a permit for HVAC replacement, national prices in HVAC replacement cost, and the hiring checklist in hiring an HVAC contractor.
What this does not tell you
Our HVAC group combines warm air, gas and refrigeration permits, so one furnace job can appear more than once. The file is missing permits issued from about July to mid-September 2025. PAULIE is finaling permits more slowly than the old system, which pulls recent times up.
How we know this
Rules are quoted from City of Saint Paul DSI pages and handouts read 23 October 2026 (license terms read 22 October 2026). Permit counts are City of Saint Paul warm air, mechanical and gas permits on homes, October 2023 to September 2026, from the City's old permit feed and PAULIE; finished share uses permits a year or more old, and days to final is the middle permit's issue-to-final time.
Numbers come from City of Saint Paul building and trade permits (the City's old approved-permits file up to June 2025, and the City's PAULIE permit system since September 2025), with the contractor named on each permit, data through October 22, 2026. Nobody paid to be on this page and nobody can.
Questions
- Do I need a permit to replace a furnace in Saint Paul?
Yes. DSI's furnace page says air conditioner and furnace installations need an electrical permit plus the Warm Air / Ventilation / General Sheet Metal permit and a mechanical permit. A furnace replacement also needs a whole-house heat loss calculation.
- Can a homeowner pull an HVAC permit in Saint Paul?
Yes, for a single-family home you own and legally homestead, if you do the work yourself, with the City's homeowner warm air and mechanical affidavit. Duplex owners must live in the side being worked on. Rentals and buildings of three or more units need a City-licensed warm air contractor.
- How much is an HVAC permit in Saint Paul?
The electrical part has a published fee: $15 per unit installed per circuit, or no charge when it is on a permit with other electrical work and no new circuit, with an $85 minimum and a $1 minimum state surcharge. DSI's pages we read do not publish the warm air or gas burner amounts; PAULIE calculates them when you apply.
- How long does an HVAC permit take in Saint Paul?
The usual Saint Paul HVAC and gas permit in our file was finaled 164 days after it was issued, and only 55.5% of permits a year or more old had been finaled. Ask the installer when it will book the final.
- What license does a furnace installer need in Saint Paul?
Minnesota has no state HVAC license but requires a $25,000 mechanical contractor bond filed with DLI. Saint Paul adds its own Warm Air / Ventilation license, which needs a Saint Paul Master Warm Air or Ventilation Certificate of Competency, and separate gas burner and refrigeration trade licenses.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- Saint Paul building permit search: how to look up permits on an address
- Ames building permit search: how to look up permits on an address
- Do I need an HVAC permit in Ames? Yes: what is exempt, homeowner permits, the $56.23 base fee and inspections
- Do I need an HVAC permit in Anaheim? The mechanical permit for a furnace or AC change-out, fees and inspections
For one city
- When is a permit required? — City of Saint Paul DSI (accessed 2026-10-23)
- Air Conditioner / Furnace / Boiler Installation — City of Saint Paul DSI (accessed 2026-10-23)
- Warm Air / Ventilation permits — City of Saint Paul DSI (accessed 2026-10-23)
- Mechanical permits overview — City of Saint Paul DSI (accessed 2026-10-23)
- Gas Burner / Oil Burner — City of Saint Paul DSI (accessed 2026-10-23)
- Homeowner's Warm Air / Ventilation and Mechanical Permits Affidavit — City of Saint Paul DSI (accessed 2026-10-23)
- Requirements for New Home Furnace Installations and Furnace Replacements — City of Saint Paul DSI (accessed 2026-10-23)
- Ventilation / Warm Air license — City of Saint Paul DSI (2026-10-22)