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Accessory Dwelling Unit (ADU) in St. George, Utah

Required for construction of a secondary dwelling unit on a residential property in St. George, including basement apartments, detached cottages, and garage conversions. Utah HB 82 (2021) requires most cities to allow internal ADUs.

Verified 2026-07-23 · Source

When you need this permit

  • Property must be zoned to allow ADUs under St. George City Code — contact Planning and Zoning at (435) 627-4100
  • Separate entrance from primary dwelling
  • Egress windows in all basement bedrooms (5.7 sq ft minimum opening, sill no higher than 44 inches above floor)
  • 1-hour fire separation required between attached/internal ADU and primary dwelling
  • Adequate parking as required by zoning

Required documents

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Fee schedule

Building PermitADU is new residential construction, assessed on project valuation per St. George's published 1997 UBC building permit fee schedule (sgcityutah.gov Building Fee Sheet PDF, re-fetched and confirmed live 2026-07-01) — the same table used for all residential construction; St. George's building/P&Z pages do not publish a separate ADU fee schedule. Minimum $60.60; plan check 65%; D.O.C. 1%. Under Utah law, impact fees for internal or attached ADUs may be reduced — confirm with the Building Department (kept as a tips note, not a confidence downgrade).
Valuation-based per the 1997 Uniform Building Code fee scale (based on total construction value)
Minimum PermitSt. George Building Fee Sheet
$60.60
Reinspection FeeSt. George City Impact Fees document (effective 4/21/21)
$47.00 per hour (minimum one-half hour)

Review timeline

Plan reviewTypical estimate — confirm current times with the St. George building department
~14–30 business days

How long did your Accessory Dwelling Unit (ADU) permit actually take in St. George?

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

Inspection process

  1. 1

    Foundation

    Footings, forms, rebar — before concrete pour

  2. 2

    Framing

    Structure, fire separation, egress windows

  3. 3

    MEP Rough-In

    Mechanical, electrical, plumbing rough-ins before walls closed

  4. 4

    Insulation

    Insulation and vapor barrier before drywall

  5. 5

    Final

    All work complete, smoke/CO detectors installed (one CO detector per habitable level), address posted, ready for occupancy

See the full St. George inspection guide — scheduling & re-inspection fees →

Tips

  • Utah HB 82 (2021) requires most cities to allow internal ADUs — contact St. George Planning and Zoning to confirm your property qualifies and to understand any local rules.
  • Basement ADU bedrooms must have egress windows with a minimum 5.7 sq ft opening and a sill height no more than 44 inches above the floor, per IRC requirements enforced in St. George.
  • A rental business license from St. George is typically required before renting an ADU — contact St. George Business Licensing at (435) 627-4100.
  • Soils reports are required for all new construction in St. George — budget accordingly.

Frequently asked questions

St. George requires an accessory dwelling unit (adu) permit for: Property must be zoned to allow ADUs under St. George City Code — contact Planning and Zoning at (435) 627-4100; Separate entrance from primary dwelling; Egress windows in all basement bedrooms (5.7 sq ft minimum opening, sill no higher than 44 inches above floor); 1-hour fire separation required between attached/internal ADU and primary dwelling; Adequate parking as required by zoning. If your project isn't listed, confirm with St. George Building Department at (435) 627-4100 before starting work.

ADU permit fees in St. George are valuation-based using the 1997 UBC fee scale, with a minimum of $60.60. Plan check is 65% of the permit fee, plus a 1% D.O.C. surcharge. Impact fees may be reduced for internal or attached ADUs under Utah law — confirm with the Building Department at (435) 627-4100.

Plan review for an accessory dwelling unit (adu) permit in St. George typically runs 14–30 business days. This is an estimate, not a published figure — confirm current review times with St. George Building Department at (435) 627-4100.

You'll need: Permit Application (CityInspect); Building Plans; Site Plan; Soils / Geotechnical Report; Zoning Compliance. See the required-documents checklist on this page for details on each.

St. George requires 5 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation, Framing, MEP Rough-In, Insulation, Final. Schedule each through St. George Building Department ((435) 627-4100).

Apply through St. George Building Department at 61 S Main St, St. George, UT 84770. Phone: (435) 627-4100, email: building@sgcity.org. Office hours: Mon–Fri 8:00 AM – 5:00 PM. Official information: https://sgcityutah.gov/departments/community_development/building_department.php.

St. George, Utah has adopted: 2024 International Building Code (IBC), including Appendices C and J — Utah Code § 15A-2-103(1)(a); CURRENT as of 7/1/2026 (statute version headed 'Effective 7/1/2026 (Superseded 1/1/2027)', confirmed by direct fetch 2026-07-16). Supersedes the 2021 IBC, which governed through 6/30/2026.; 2021 International Residential Code (IRC) — Utah Code § 15A-2-103(1)(b); UNCHANGED by the 7/1/2026 code cycle — remains 2021 and continues in force (confirmed by direct statute fetch 2026-07-16).; Appendix AQ of the 2021 International Residential Code — Utah Code § 15A-2-103(1)(c) (confirmed by direct statute fetch 2026-07-16).; 2024 International Plumbing Code (IPC) — Utah Code § 15A-2-103(1)(d); CURRENT as of 7/1/2026 (confirmed by direct statute fetch 2026-07-16). Supersedes the 2021 IPC, which governed through 6/30/2026.; 2024 International Mechanical Code (IMC) — Utah Code § 15A-2-103(1)(e); CURRENT as of 7/1/2026 (confirmed by direct statute fetch 2026-07-16). Supersedes the 2021 IMC, which governed through 6/30/2026.; 2024 International Fuel Gas Code (IFGC) — Utah Code § 15A-2-103(1)(f); CURRENT as of 7/1/2026 (confirmed by direct statute fetch 2026-07-16). Supersedes the 2021 IFGC, which governed through 6/30/2026.; 2023 National Electrical Code (NEC) — Utah Code § 15A-2-103(1)(g); UNCHANGED by the 7/1/2026 code cycle — remains 2023 (confirmed by direct statute fetch 2026-07-16).; 2024 International Energy Conservation Code (IECC) — Utah Code § 15A-2-103(1)(h); CURRENT as of 7/1/2026 (confirmed by direct statute fetch 2026-07-16). ONE statewide edition — the statute does not split residential vs. commercial IECC editions. Supersedes the 2021 IECC, which governed through 6/30/2026.; 2024 International Existing Building Code (IEBC) — Utah Code § 15A-2-103(1)(i); CURRENT as of 7/1/2026 (confirmed by direct statute fetch 2026-07-16). Supersedes the 2021 IEBC, which governed through 6/30/2026.; Residential provisions of the 2024 International Swimming Pool and Spa Code (ISPSC) — Utah Code § 15A-2-103(1)(n); CURRENT as of 7/1/2026 (confirmed by direct statute fetch 2026-07-16). Supersedes the 2021 ISPSC, which governed through 6/30/2026.; NOTE (2026-07-16 corpus-staleness fix): This file previously stated the 2021 editions as current and only forecasted the 7/1/2026 flip; the effective date has now passed and the entries above have been corrected to state the 2024 editions (per §15A-2-103(1)(a)/(d)/(e)/(f)/(h)/(i)/(n)) as current, with the superseded 2021 editions preserved as historical context. IRC (2021) and NEC (2023) were NOT changed — verified unchanged directly against the live statute. The International Fire Code (IFC) is NOT adopted anywhere in Utah Code § 15A-2-103 — the statute has no IFC subsection; St. George's own building department page does not independently cite an IFC edition, so no IFC entry appears in this list.. Local amendments apply — see the St. George overview page for the full list.

Most likely yes. Utah HB 82 (2021) requires cities to allow internal ADUs. St. George may also allow detached ADUs depending on zoning. Contact St. George Planning and Zoning at (435) 627-4100 to confirm your property qualifies and what ADU types are permitted.

Sources & verification

Verified against official sources. Last reviewed 2026-07-23.

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 St. George building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

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Accessory Dwelling Unit (ADU) in other cities

Bountiful, UtahDraper, UtahEagle Mountain, UtahKaysville, UtahLayton, UtahLehi, UtahLogan, UtahNorth Salt Lake, Utah

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