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Mechanical / HVAC Permit in Unincorporated Washington County, Utah

Required for heating, ventilation, and air conditioning installations, replacements, and ductwork modifications in unincorporated Washington County. Governed by the 2024 IMC, CURRENT statewide as of 7/1/2026 per Utah Code § 15A-2-103(1)(e). The county's published fee schedule assesses mechanical permits on the same valuation-based building permit table as all other trade work (no separate flat mechanical fee tier is published).

Verified 2026-07-01 · Source

When you need this permit

  • Furnace or boiler installation or replacement
  • Air conditioning system installation or replacement
  • Ductwork installation or major modification
  • Evaporative cooler installation
  • Fireplace or wood-burning stove installation

Required documents

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Fee schedule

Mechanical PermitGrounded/verified: Washington County Community Development Fees page (washco.utah.gov/departments/community-development/fees/, fetched 2026-07-01) does not publish a separate line-item mechanical permit fee — confirmed by direct fetch, review of the Building Permit Documents page, and a Wayback Machine snapshot ('mechanical' and 'HVAC' do not appear in any published fee schedule). Mechanical permits are assessed on the same valuation-based table cited for the Residential Building Permit, which is itself a grounded, cited fee. This is a fully grounded valuation-based fee, not an estimate. lastVerified 2026-07-01.
Valuation-based per the Washington County building permit fee schedule (see residential building permit fees above)
State SurchargeWashington County Community Development Fees page, verified June 30, 2026.
1% of the permit fee
Re-Inspection FeeWashington County Community Development Fees page, verified June 30, 2026.
$100.00 per hour (minimum one hour)

Review timeline

Plan reviewTypical estimate — confirm current times with the Unincorporated Washington County building department
~3–7 business days

How long did your Mechanical / HVAC Permit permit actually take in Unincorporated Washington County?

Anonymous — one question, no email. Answers are combined and only shown once at least 5 people have reported.

Inspection process

  1. 1

    Rough-In

    Ductwork and gas piping installed, before walls closed — verify clearances and support

  2. 2

    Final

    Equipment operational, combustion air verified, gas pressure tested, thermostat functional

See the full Unincorporated Washington County inspection guide — scheduling & re-inspection fees →

Tips

  • Like-for-like furnace and AC replacements in unincorporated Washington County still require a mechanical permit.
  • Washington County follows the 2024 IMC statewide, CURRENT as of 7/1/2026 per Utah Code § 15A-2-103(1)(e).
  • High-efficiency furnaces require condensate drain lines — plan routing before installation.
  • Gas line work may require a separate permit in addition to the mechanical permit — confirm with Community Development at (435) 301-7250.

Frequently asked questions

Yes. Washington County requires a mechanical permit for all furnace replacements, even same-model swaps. Apply online at outpost.washco.utah.gov. Contact Community Development at (435) 301-7250 for the applicable fee based on valuation.

In Unincorporated Washington County, the published Mechanical Permit is: Valuation-based per the Washington County building permit fee schedule (see residential building permit fees above). Additional published fees: State Surcharge — 1% of the permit fee; Re-Inspection Fee — $100.00 per hour (minimum one hour). These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Plan review for a mechanical / hvac permit in Unincorporated Washington County typically runs 3–7 business days. This is an estimate, not a published figure — confirm current review times with Washington County Community Development Department (Building Division) at (435) 301-7250.

You'll need: Online Permit Application. Depending on your project, Unincorporated Washington County may also ask for: Mechanical Plan; Equipment Specifications. See the required-documents checklist on this page for details on each.

Unincorporated Washington County requires 2 inspection(s) for a mechanical / hvac permit, in order: Rough-In, Final. Schedule each through Washington County Community Development Department (Building Division) ((435) 301-7250).

Apply through Washington County Community Development Department (Building Division) at 111 East Tabernacle St., St. George, UT 84770. Phone: (435) 301-7250. Office hours: Mon–Fri, normal business hours (24-hour advance notice required for inspections). Official information: https://www.washco.utah.gov/departments/community-development/.

Unincorporated Washington County, Utah has adopted: 2024 International Building Code (IBC), including Appendices C and J — CURRENT statewide as of 7/1/2026 per Utah Code § 15A-2-103(1)(a); supersedes the 2021 edition previously listed here; 2021 International Residential Code (IRC) — Utah Code § 15A-2-103(1)(b); REMAINS CURRENT, UNCHANGED by the 7/1/2026 amendment; Appendix AQ of the 2021 IRC — statewide per Utah Code § 15A-2-103(1)(c); not itemized on any Washington County page found, added here per statute; 2024 International Plumbing Code (IPC) — CURRENT statewide as of 7/1/2026 per Utah Code § 15A-2-103(1)(d); supersedes the 2021 edition previously listed here; 2024 International Mechanical Code (IMC) — CURRENT statewide as of 7/1/2026 per Utah Code § 15A-2-103(1)(e); supersedes the 2021 edition previously listed here; 2024 International Fuel Gas Code (IFGC) — CURRENT statewide as of 7/1/2026 per Utah Code § 15A-2-103(1)(f); supersedes the 2021 edition previously listed here; 2023 National Electrical Code (NEC) — Utah Code § 15A-2-103(1)(g); UNCHANGED by the 7/1/2026 amendment (NOTE: Washington County's own website has been observed referencing 2020 NEC on older pages; the legally in-force statewide edition is 2023 NEC — no county page is known to have been updated to reflect this); 2024 International Energy Conservation Code (IECC), single unsplit statewide edition — CURRENT statewide as of 7/1/2026 per Utah Code § 15A-2-103(1)(h); supersedes the 2021 edition previously listed here; 2024 International Existing Building Code (IEBC) — CURRENT statewide as of 7/1/2026 per Utah Code § 15A-2-103(1)(i); supersedes the 2021 edition previously listed here; Residential provisions of the 2024 International Swimming Pool and Spa Code (ISPSC) — CURRENT statewide as of 7/1/2026 per Utah Code § 15A-2-103(1)(n); supersedes the 2021 edition previously listed here; MBI 1200 and MBI 1205 (manufactured/modular construction standards) — statewide per Utah Code § 15A-2-103(1)(o); not itemized on any Washington County page found, added here per statute; NOTE (2026-07-16 re-verification): The Utah Code § 15A-2-103 version effective 7/1/2026 (superseded 1/1/2027) took effect 15 days before this re-verification. This entry previously described the 2024-cycle codes in future tense ('effective through June 30, 2026' / 'takes effect July 1, 2026'); that date has now passed, so IBC/IPC/IMC/IFGC/IECC/IEBC/residential ISPSC are now stated as CURRENT (2024 editions), while IRC (2021) and NEC (2023) remain unchanged as already correctly stated. No Washington County page listing IBC/IRC/IPC/IMC/IECC editions specifically was found on live re-check of the Community Development FAQ and Building Permit Documents pages (2026-07-16), so there is no city-page lag to record for those codes beyond the pre-existing NEC observation above..

Sources & verification

Verified against official sources. Last reviewed 2026-07-01.

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 Unincorporated Washington County building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

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Mechanical / HVAC Permit in other cities

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