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Mechanical / HVAC Permit in Great Falls, Montana

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Required for heating, ventilation, air conditioning, fuel gas, and related mechanical installations in Great Falls. Governed by the 2021 International Mechanical Code (IMC) and 2021 International Fuel Gas Code (IFGC) as adopted by the City of Great Falls. Homeowners may obtain a Homeowner's Mechanical Permit for owner-occupied residences.

Verified 2026-07-02 · Source

From$34.39Permit Issuance Fee — see all 10 fees below

When you need this permit

Required documents

Fee schedule

Fee typeAmountNotes
Permit Issuance Fee$34.39Resolution No. 10374, Exhibit A, Mechanical Permit Fees — Effective August 7, 2018; verified visually from the rendered resolution PDF page
Furnace/burner installation or relocation — forced-air or gravity-type, up to and including 100,000 Btu/h$19.04Resolution No. 10374, Exhibit A, Mechanical Permit Fees, Item 1 — verified visually from the rendered resolution PDF page (text extraction had column misalignment on this page; figure confirmed by direct visual read of the source PDF)
Furnace/burner installation or relocation — over 100,000 Btu/h$22.72Resolution No. 10374, Exhibit A, Mechanical Permit Fees, Item 1 — verified visually
Floor furnace installation or relocation, including vent$19.04Resolution No. 10374, Exhibit A, Mechanical Permit Fees, Item 1 — verified visually
Gas piping system — per outlet$7.00Resolution No. 10374, Exhibit A, Mechanical Permit Fees, Item 2 — verified visually
Mobile/Manufactured Home hookup$19.04Resolution No. 10374, Exhibit A, Mechanical Permit Fees, Item 3 — verified visually
Repair, alteration, or addition to heating/cooling/absorption appliance or system$17.68Resolution No. 10374, Exhibit A, Mechanical Permit Fees, Item 5 — verified visually
Ventilation fan connected to a single duct$10.07Resolution No. 10374, Exhibit A, Mechanical Permit Fees, Item 9 — verified visually
Re-inspection Fee$67.63 per hour, minimum 1-hour chargeCity of Great Falls Homeowner's Mechanical Permit Application (Updated 3/2026) — current rate; supersedes the $62.62/hr figure in Resolution 10374
Investigation Fee (work commenced before permit issuance)Equal to the permit feeResolution No. 10374, Exhibit A, Mechanical Permit Fees, Item 5 (Other Inspection and Fees)

Review timeline

~110 business days

Typical estimate — confirm current times with the Great Falls building department

Inspection process

  1. 1

    Gas Piping Pressure Test

    Required before concealing gas piping

  2. 2

    Rough-In

    Ductwork and mechanical equipment rough-in before walls closed

  3. 3

    Final

    Equipment operational, combustion air and venting verified

Tips

Frequently asked questions

Do I need a permit to replace my furnace in Great Falls?
Yes. Furnace replacement requires a mechanical permit. For a standard forced-air furnace up to 100,000 Btu/h, the fee is $34.39 (issuance) plus $19.04 (unit fee) per Resolution No. 10374, Exhibit A.

Sources & verification

Verified against official sources. Last reviewed 2026-07-02.

Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Great Falls building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

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