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Accessory Dwelling Unit (ADU) Permit in Gilbert, Arizona

Accessory Dwelling Units in the Town of Gilbert are regulated under Land Development Code Section 5.2.3. Each lot may have one (1) detached ADU and one (1) attached ADU; parcels over one acre may have an additional detached ADU if it is a restricted-affordable unit. ADU must be less than 75% of the primary dwelling's gross square footage. ADUs 1,000 SF and under go directly through Building Permits (OneStopShop); ADUs over 1,000 SF require an Administrative Use Permit through Planning first, then a Building Permit. Applications at onestopshop.gilbertaz.gov.

Verified 2026-07-16 · Source

When you need this permit

  • Submit through OneStopShop portal at onestopshop.gilbertaz.gov
  • ADU must be less than 75% of the primary dwelling's gross square footage
  • ADUs ≤ 1,000 SF: Building Permit only through OneStopShop
  • ADUs > 1,000 SF: Administrative Use Permit through Planning first, then a Building Permit
  • Each lot limited to one (1) detached ADU and one (1) attached ADU; additional detached ADU allowed on parcels >1 acre if restricted-affordable
  • Architectural articulation is required
  • Soils report required unless subdivision has one on file or a signed soils report waiver is provided (call 480-503-6700)
  • All utility services for ADU must come from the primary structure's utility connections (a private in-line meter is allowed but is not read by the utility company)
  • Separate address for ADU may be requested but is not required
  • Accessory structures over 200 SF require a Building Permit (but not a Use Permit)
  • HOA/CC&R approval may be required in addition to Town permit

Required documents

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Fee schedule

Building Permit Fee — valuation-basedSource: Town of Gilbert Development Services Fee Schedules (doc 5883), Building Permit and Plan Review Fees Table, effective July 1, 2025, Resolution 4563. ADU permit fee calculated from the standard Building Permit Fee valuation-based table.
Same valuation-based table as residential construction; $50.00 minimum for work valued $1.00–$1,100.00
Plan Review FeeSource: Town of Gilbert Development Services Fee Schedules (doc 5883), effective July 1, 2025, Resolution 4563.
65% of the calculated Building Permit Fee
Administrative Use Permit Fee (if ADU > 1,000 SF)Source: Town of Gilbert Development Services Fee Schedules (doc 5883), Planning & Development Fees and Charges — Administrative Use Permit, effective July 1, 2025, Resolution 4563.
$1,000
Development FeesPer the ADU Guide (doc 50846, February 2025): 'development fees may apply.' System Development Fees for single-unit residential: Parks & Recreation $9,358; Traffic Signals $1,754; Roads $3,010; Police $1,138; Fire $1,447 (per the July 1, 2025 fee schedule, doc 5883, adopted July 1, 2024 per Town Council April 16, 2024). Contact Development Services to confirm whether and what SDFs apply to a specific ADU.
May apply — contact Development Services for current development fee schedule

Review timeline

Plan reviewGilbert’s published plan-review target
8–12 business days

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

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

Inspection process

  1. 1

    Foundation / Slab Inspection

    Inspection of foundation and slab before pouring concrete

  2. 2

    Rough Framing / Systems Inspection

    Framing, rough plumbing, mechanical, and electrical inspections

  3. 3

    Final Inspection

    Final inspection confirming ADU complete and ready for occupancy

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

Tips

  • ADUs ≤ 1,000 SF go directly through Building Permits (no Planning approval needed). ADUs > 1,000 SF need an Administrative Use Permit from Planning first ($1,000 fee).
  • The ADU must be less than 75% of the primary dwelling's gross square footage.
  • Utility connections: ADU utility services must come from the primary structure's connections. A private in-line meter is allowed but is not read by the utility company.
  • Architectural articulation is a required design element — confirm requirements with Development Services.
  • A separate address is possible for the ADU but not required.
  • Check HOA and CC&R requirements in addition to Town permits — HOA approval may be needed.
  • Accessory structures (non-ADU) over 200 SF require a Building Permit (no Use Permit needed).

Frequently asked questions

Gilbert requires an accessory dwelling unit (adu) permit for: Submit through OneStopShop portal at onestopshop.gilbertaz.gov; ADU must be less than 75% of the primary dwelling's gross square footage; ADUs ≤ 1,000 SF: Building Permit only through OneStopShop; ADUs > 1,000 SF: Administrative Use Permit through Planning first, then a Building Permit; Each lot limited to one (1) detached ADU and one (1) attached ADU; additional detached ADU allowed on parcels >1 acre if restricted-affordable; Architectural articulation is required; Soils report required unless subdivision has one on file or a signed soils report waiver is provided (call 480-503-6700); All utility services for ADU must come from the primary structure's utility connections (a private in-line meter is allowed but is not read by the utility company); Separate address for ADU may be requested but is not required; Accessory structures over 200 SF require a Building Permit (but not a Use Permit); HOA/CC&R approval may be required in addition to Town permit. If your project isn't listed, confirm with Town of Gilbert Development Services Department — Plan Review and Inspection Division at (480) 503-6700 before starting work.

In Gilbert, the published Building Permit Fee — valuation-based is: Same valuation-based table as residential construction; $50.00 minimum for work valued $1.00–$1,100.00. Additional published fees: Plan Review Fee — 65% of the calculated Building Permit Fee; Administrative Use Permit Fee (if ADU > 1,000 SF) — $1,000; Development Fees — May apply — contact Development Services for current development fee schedule. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Gilbert's published plan-review target for an accessory dwelling unit (adu) permit is 8–12 business days.

You'll need: Building Permit Application; Architectural Plans; Soils Report (or Waiver); Site Plan. Depending on your project, Gilbert may also ask for: Administrative Use Permit Application (if ADU > 1,000 SF). See the required-documents checklist on this page for details on each.

Gilbert requires 3 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation / Slab Inspection, Rough Framing / Systems Inspection, Final Inspection. Schedule each through Town of Gilbert Development Services Department — Plan Review and Inspection Division ((480) 503-6700).

Apply through Town of Gilbert Development Services Department — Plan Review and Inspection Division at 90 E. Civic Center Drive, Gilbert, AZ 85296. Phone: (480) 503-6700, email: onestopshop@gilbertaz.gov. Office hours: Monday–Thursday: 7:00 AM–6:00 PM; Friday: Closed (Town Hall operates a 4-day/10-hour week; confirmed live on the Development Services department page 2026-07-16). Official information: https://www.gilbertaz.gov/departments/development-services.

Each lot may have one (1) detached ADU and one (1) attached ADU. Parcels over one acre in size may have an additional detached ADU if it is a restricted-affordable unit. See Land Development Code Section 5.2.3.

Yes, unless your subdivision already has one on file with the Town, or you provide a signed soils report waiver. Call (480) 503-6700 to check if your subdivision has one on file.