Mechanical / HVAC Permit in Gillette, Wyoming

Gillette requires a mechanical / hvac permit for: Residential new HVAC covers up to 2 heating units, A/C unit, vents, ducts, bath fans, dryer vents under one flat fee; additional units are billed per-unit; Residential replacement HVAC (furnace, woodstove, heating unit, A/C, boiler) is billed per unit; Commercial new/replacement HVAC has its own per-unit and flat-fee structure; Gas piping systems are billed by outlet count; Contractor must hold a City of Gillette Class D HVAC/Mechanical or Gas Pipefitters contractor license. If your project isn't listed, confirm with City of Gillette Development Services — Building Division at (307) 686-5260 before starting work.

$10.00 for a gas piping system of 1 to 4 outlets, or $15.00 per outlet for systems of 5 or more outlets, per City Code § 5-IV-3(c).

Plan review for a mechanical / hvac permit in Gillette typically runs 0–5 business days. This is an estimate, not a published figure — confirm current review times with City of Gillette Development Services — Building Division at (307) 686-5260.

You'll need: Mechanical Permit Application (via EnerGov Self Service). See the required-documents checklist on this page for details on each.

Gillette requires 3 inspection(s) for a mechanical / hvac permit, in order: Rough Mechanical, Gas, Final. Schedule each through City of Gillette Development Services — Building Division ((307) 686-5260).

Apply through City of Gillette Development Services — Building Division at City Hall, 201 E. 5th St., 2nd Floor, Gillette, WY 82716. Phone: (307) 686-5260, email: Not published on city site — use "Send an E-mail" contact form on the Building Division page or main line gillette@gillettewy.gov. Office hours: Mon–Fri (contact department for current hours); permits/plans/licenses/inspections managed via EnerGov Self Service online portal (registration required). Official information: https://www.gillettewy.gov/Departments/Development-Services/Building-Division.

Gillette, Wyoming has adopted: International Building Code (IBC), 2021 Edition — including Appendix C, adopted by City of Gillette Code Chapter 5, Article I § 5-I-2 (Revised 6-16-2026). CHANGED 2026-07-16 audit: the live § 5-I-2.A text now reads "2021 Edition, including Appendix C" and no longer cites Ord. 4052 (12-17-2024), which had adopted the 2024 IBC edition with Appendices C and H per the source PDF as of the prior 2026-07-01 verification; the 2024-edition adoption no longer appears in the current ordinance text.; International Residential Code (IRC), 2021 Edition — including Appendices AA, AB, AC, AE, AN, AQ, and AW (AW 3D Printed Construction), adopted § 5-I-3 (Revised 6-16-2026). CHANGED 2026-07-16 audit: the live § 5-I-3.A text now reads "2021 Edition" with this different appendix set (previously 2024 Edition, Appendices CA, CB, BA, CE, BB, BM per Ord. 4052, 12-17-2024, which no longer appears in the current ordinance text).; International Plumbing Code (IPC), 2021 Edition — including Appendices B, D, E, adopted § 5-I-4 (Revised 6-16-2026) — NOTE: Gillette uses the IPC, not the Uniform Plumbing Code. CHANGED 2026-07-16 audit: edition now reads 2021 (previously 2024 per Ord. 4052, 12-17-2024, no longer cited); appendices B, D, E unchanged.; International Mechanical Code (IMC), 2021 Edition — adopted § 5-I-5 (Revised 6-16-2026). CHANGED 2026-07-16 audit: edition now reads 2021 (previously 2024 per Ord. 4052, 12-17-2024, no longer cited).; National Electrical Code — City Code § 5-I-6 (Revised 6-16-2026) (including Article 80/Annex H). CHANGED 2026-07-16 audit: the live § 5-I-6.A paragraph now contains two different edition references in the same sentence — "...adopted by reference the National Electrical Code, 2023 Edition..." and later "...of the National Electrical Code, 2026 Edition, including Article 80, are hereby referred to, adopted..." — with the amendment history newly listing Ord. 4081 (6-16-2026) as the latest ordinance for this section. The ordinance's own text does not reconcile the two edition years; previously cited cleanly as 2023 Edition only.; International Fuel Gas Code (IFGC), 2021 Edition — including Appendices A, B, C, D, adopted § 5-I-7 (Revised 6-16-2026). CHANGED 2026-07-16 audit: edition now reads 2021 (previously 2024 per Ord. 4052, 12-17-2024, no longer cited); appendices A, B, C, D unchanged.; International Fire Code (IFC), 2021 Edition — including Appendices B, C, D, E, F, and G, adopted § 5-I-8 (Revised 6-16-2026). CHANGED 2026-07-16 audit: edition now reads 2021 and Appendices H and I are absent (previously 2024 Edition with Appendices B–I per Ord. 4052, 12-17-2024, no longer cited).; International Existing Building Code (IEBC), 2021 Edition — adopted § 5-I-9 (Revised 6-16-2026). CHANGED 2026-07-16 audit: § 5-I-9.A reads "2021 Edition" (previously cited as 2024 Edition; the current text carries no ordinance citation for the edition line).; Uniform Code for the Abatement of Dangerous Buildings, 1997 Edition — adopted § 5-I-10 (Revised 6-16-2026); edition unchanged, only the chapter revision date-stamp updated at the 2026-07-16 audit.. Local amendments apply — see the Gillette overview page for the full list.