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Accessory Dwelling Unit (ADU) in Layton, Utah

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

Verified 2026-07-16 · Source

When you need this permit

  • Property zoned for ADU use (check Layton zoning map)
  • Separate entrance from primary dwelling
  • Adequate parking per Layton zoning code
  • Fire separation between units if attached

Required documents

Check off what you have — your progress is saved on this device.

Not ready yet0 of 2 required documents checked.

This checker covers one permit. A full project usually triggers several — our paid checklist will assemble all of them, from $29

Fee schedule

ADU Building PermitAssessed on project valuation per Layton City's building permit fee schedule, cited: Layton City Consolidated Fee Schedule, effective July 1, 2026 (verified live at laytoncityutah.gov/downloads/CD/feesched.pdf, p.16 "Building permit fees"). An ADU is new residential construction/conversion and Layton does not publish a separate ADU fee category, so it is charged under the standard building valuation table; the underlying statewide standard (Utah HB82, 2021, internal ADUs) is codified and current — no fee-schedule flux affects this determination
Valuation-based per building permit fee table (see residential building permit fees); plan check is 40% of permit fee (residential)
Re-inspection FeeLayton City Consolidated Fee Schedule, effective July 1, 2026 — "Permit inspection fees: re-inspection $50", p.16. Re-verified 2026-07-16 against the live PDF (footer + URL param yr=20260701 both confirm July 1, 2026 as the document's own stated effective date, superseding a stale internal 'January 5, 2026' citation); the $50 figure is unchanged.
$50 per occurrence

Review timeline

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

How long did your Accessory Dwelling Unit (ADU) permit actually take in Layton?

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, address posted, ready for occupancy

See the full Layton inspection guide — scheduling & re-inspection fees →

Tips

  • Utah HB 82 (2021) requires most cities to allow at least internal ADUs — contact Layton planning to confirm whether detached ADUs are also permitted.
  • Basement ADU bedrooms must have egress windows with a minimum 5.7 sq ft net clear opening per the 2021 IRC.
  • Contact Layton planning at (801) 336-3760 to verify ADU eligibility for your property before investing in design.
  • A Layton business license may be required before renting an ADU.

Frequently asked questions

Layton requires an accessory dwelling unit (adu) permit for: Property zoned for ADU use (check Layton zoning map); Separate entrance from primary dwelling; Adequate parking per Layton zoning code; Fire separation between units if attached. If your project isn't listed, confirm with Layton City Building Division at (801) 336-3760 before starting work.

ADU building permit fees in Layton are valuation-based per the Consolidated Fee Schedule (effective July 1, 2026) — the same table used for all building permits. Residential plan check is 40% of the permit fee. Under Utah law, impact fees for internal or attached ADUs may be reduced or waived — confirm with the building department.

Plan review for an accessory dwelling unit (adu) permit in Layton typically runs 14–30 business days. This is an estimate, not a published figure — confirm current review times with Layton City Building Division at (801) 336-3760.

You'll need: Building Plans; Site Plan. Depending on your project, Layton may also ask for: Fire Separation Details. See the required-documents checklist on this page for details on each.

Layton requires 5 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation, Framing, MEP Rough-In, Insulation, Final. Schedule each through Layton City Building Division ((801) 336-3760).

Apply through Layton City Building Division at 437 N Wasatch Dr, Layton, UT 84041. Phone: (801) 336-3760. Office hours: Mon–Fri 8:00 AM – 5:00 PM. Official information: https://www.laytoncity.org/LC/CD/BuildingDivision.

Layton, Utah has adopted: 2024 International Building Code (IBC), including Appendices C and J — Layton Design Criteria & Adopted Codes (Revised 7/1/26), citing Utah Code § 15A-2-103(1)(a); effective 2026-07-01, superseded the 2021 edition; 2021 International Residential Code (IRC), including Appendices AQ and AE — Layton Design Criteria & Adopted Codes (Revised 7/1/26); Utah Code § 15A-2-103(1)(b)/(c)/(k); unchanged by the 7/1/2026 code cycle; 2024 International Plumbing Code (IPC) — Layton Design Criteria & Adopted Codes (Revised 7/1/26); Utah Code § 15A-2-103(1)(d); effective 2026-07-01, superseded the 2021 edition; 2024 International Mechanical Code (IMC) — Layton Design Criteria & Adopted Codes (Revised 7/1/26); Utah Code § 15A-2-103(1)(e); effective 2026-07-01, superseded the 2021 edition; 2024 International Fuel Gas Code (IFGC) — Layton Design Criteria & Adopted Codes (Revised 7/1/26); Utah Code § 15A-2-103(1)(f); effective 2026-07-01, superseded the 2021 edition; 2024 International Fire Code (IFC) — Layton Design Criteria & Adopted Codes (Revised 7/1/26); IFC is governed by Utah Code Title 15A Chapter 5 (state fire code), not § 15A-2-103; effective 2026-07-01 per Layton's own document, superseding the 2021 edition; 2023 National Electrical Code (NEC) — Layton Design Criteria & Adopted Codes (Revised 7/1/26); Utah Code § 15A-2-103(1)(g); unchanged by the 7/1/2026 code cycle; 2024 International Energy Conservation Code (IECC) — Layton Design Criteria & Adopted Codes (Revised 7/1/26); Utah Code § 15A-2-103(1)(h); effective 2026-07-01, superseded the 2021 edition. NOTE: the prior (eff. 7/1/25) version of Layton's document split this into separate 'residential' and 'commercial' IECC lines plus a '2015 International Residential Code Chapter 11, Energy Efficiency' line; the current document (Revised 7/1/26) lists a single 2024 IECC line with no such split — that older split is preserved here only as a historical fact about the prior document.; 2024 International Existing Building Code (IEBC) — Layton Design Criteria & Adopted Codes (Revised 7/1/26); Utah Code § 15A-2-103(1)(i); effective 2026-07-01, superseded the 2021 edition; 2024 International Swimming Pool and Spa Code (ISPSC), residential provisions — Layton Design Criteria & Adopted Codes (Revised 7/1/26); Utah Code § 15A-2-103(1)(n); effective 2026-07-01, superseded the 2021 edition; NOTE (verified 2026-07-16): Confirmed directly against Layton's live PDF (laytoncity.org/pdf/CD/BuildingDivision/Document/DesignCriteria.pdf), which is itself dated 'Revised 7/1/26' and already lists the 2024 editions of IBC, IPC, IMC, IFGC, IFC, IECC, IEBC, and ISPSC, with the 2021 IRC and 2023 NEC unchanged. Layton's own document is current and matches Utah Code § 15A-2-103 (version effective 7/1/2026, superseded 1/1/2027), confirmed directly at le.utah.gov.. Local amendments apply — see the Layton overview page for the full list.

Most likely yes for internal ADUs. Utah state law (HB 82, 2021) requires cities to allow internal ADUs. Layton may also allow detached ADUs depending on zoning. Contact Layton planning to confirm your property qualifies before starting design.

Sources & verification

Verified against official sources. Last reviewed 2026-07-16.

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