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Accessory Dwelling Unit (ADU) Permit in Tempe, Arizona

Tempe City Council adopted ADU regulations in compliance with Arizona House Bill 2720, which requires municipalities with populations of 75,000 or more to permit ADUs on all lots where single-family dwellings are allowed. On all lots with a single-family dwelling, one attached and one detached ADU are allowed. Lots of one acre (43,560 sq ft) or more may have one additional ADU if at least one is income-restricted affordable housing (80% AMI). ADUs must comply with Tempe's adopted 2018 I-Codes and the adopted ADU ordinance. ADU permits are applied for through the Tempe Citizen Access Portal. Tempe publishes approved standard ADU plan designs and an ADU Development Guide.

Verified 2026-06-29 · Source

When you need this permit

  • Allowed on all lots with an existing single-family dwelling: one attached ADU and one detached ADU
  • Lots one acre or larger may have one additional ADU if at least one is income-restricted at 80% AMI
  • Maximum livable floor area: 75% of the interior habitable floor area of the main home OR 1,000 sq ft (whichever is less) for lots under 1 acre; 75% OR 2,000 sq ft for lots 1 acre or more
  • Setbacks: rear, side, and street-side setback minimum 5 feet in all districts (unless a lesser setback exists); front yard setback consistent with the zoning district single-family standard
  • Height limited to that allowed in the zoning district (typically 30 ft); two-story ADU designs require a Use Permit (per December 17, 2025 Board of Adjustment decision)
  • Lot coverage standards of the underlying zoning district apply
  • No additional parking is required for an ADU (prohibited by HB 2720)
  • ADU is not required to match the exterior design of the main structure
  • Apply electronically through the Tempe Citizen Access Portal
  • ADU Standard Plans (pre-approved designs) are available from Tempe — see standard plan library at tempe.gov

Required documents

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Fee schedule

ADU building permit — valuation-based (Table 1-A, effective July 1, 2025)Tempe does not publish a separate ADU flat-rate fee; ADUs are permitted under the valuation-based Table 1-A. Source: Table 1-A (library.municode.com/az/tempe/codes/city_code?nodeId=APXASCFECH_TA1UIPEFE).
Per Table 1-A tiers based on construction valuation. For example, an ADU with construction valuation of $100,001–$500,000: $2,218.67 for the first $100,000 plus $12.23 per additional $1,000. Plan Review Fee is 65% of the building permit fee, collected at application.

Review timeline

Plan reviewTempe’s published plan-review target
5–15 business days

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

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

Inspection process

  1. 1

    Foundation / footing (before concrete pour)

    Foundation inspected before concrete is poured; must be approved before proceeding.

  2. 2

    Rough trades / framing (before covering)

    Rough framing, plumbing, mechanical, and electrical inspected before insulation and drywall; must be approved before covering.

  3. 3

    Final inspection

    Final inspection of all completed ADU work per approved plans and adopted codes; scheduled through Citizen Access Portal or 24-hour IVR.

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

Tips

  • Tempe allows one attached and one detached ADU on any single-family lot — no relationship required between owner and ADU occupant.
  • Two-story ADU designs require a Use Permit (Board of Adjustment decision, December 17, 2025) — plan for additional review time.
  • Tempe's ADU Standard Plan Library provides pre-approved designs; using a standard plan may reduce plan review time.
  • No additional parking is required for an ADU (prohibited by Arizona HB 2720).
  • If your lot is in an HOA area, check HOA CC&Rs — they may restrict ADUs even where city code permits them.
  • Converting an existing guest quarters to an ADU is allowed by applying for appropriate building permits.
  • For income-restricted ADU requirements on lots 1 acre or larger (third ADU), renter qualifications are based on 80% Area Median Income (AMI).

Frequently asked questions

Tempe requires an accessory dwelling unit (adu) permit for: Allowed on all lots with an existing single-family dwelling: one attached ADU and one detached ADU; Lots one acre or larger may have one additional ADU if at least one is income-restricted at 80% AMI; Maximum livable floor area: 75% of the interior habitable floor area of the main home OR 1,000 sq ft (whichever is less) for lots under 1 acre; 75% OR 2,000 sq ft for lots 1 acre or more; Setbacks: rear, side, and street-side setback minimum 5 feet in all districts (unless a lesser setback exists); front yard setback consistent with the zoning district single-family standard; Height limited to that allowed in the zoning district (typically 30 ft); two-story ADU designs require a Use Permit (per December 17, 2025 Board of Adjustment decision); Lot coverage standards of the underlying zoning district apply; No additional parking is required for an ADU (prohibited by HB 2720); ADU is not required to match the exterior design of the main structure; Apply electronically through the Tempe Citizen Access Portal; ADU Standard Plans (pre-approved designs) are available from Tempe — see standard plan library at tempe.gov. If your project isn't listed, confirm with City of Tempe Community Development Department — Building Safety Division / Permit Center at 480-350-4311 before starting work.

In Tempe, the published ADU building permit — valuation-based (Table 1-A, effective July 1, 2025) is: Per Table 1-A tiers based on construction valuation. For example, an ADU with construction valuation of $100,001–$500,000: $2,218.67 for the first $100,000 plus $12.23 per additional $1,000. Plan Review Fee is 65% of the building permit fee, collected at application.. These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Tempe's published plan-review target for an accessory dwelling unit (adu) permit is 5–15 business days.

You'll need: Contractor Affidavit. Depending on your project, Tempe may also ask for: ADU Development Guide; Adopted ADU Ordinance / Code Text Amendment; ADU Standard Plans. See the required-documents checklist on this page for details on each.

Tempe requires 3 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation / footing (before concrete pour), Rough trades / framing (before covering), Final inspection. Schedule each through City of Tempe Community Development Department — Building Safety Division / Permit Center (480-350-4311).

Apply through City of Tempe Community Development Department — Building Safety Division / Permit Center at City of Tempe City Hall, 31 E. 5th St., Tempe, AZ 85281. Phone: 480-350-4311, email: permitcenter@tempe.gov. Office hours: Contact the Permit Center at 480-350-4311 or permitcenter@tempe.gov for current hours; inspections are conducted Monday–Friday 6:30 AM–3:30 PM (inspection requests received before midnight are inspected the following business day). Official information: https://www.tempe.gov/government/community-development/building-safety/permit-center.

On any lot with a single-family dwelling, you may build one attached and one detached ADU. If your lot is 1 acre (43,560 sq ft) or larger, one additional ADU may be permitted if it is income-restricted at 80% AMI. Properties with a duplex, triplex, or multifamily building are not eligible for ADU regulations. Source: Tempe ADU page (tempe.gov/government/community-development/planning/accessory-dwelling-units-adus).

For lots under 1 acre: maximum livable floor area is 75% of the interior habitable floor area of the main house OR 1,000 sq ft, whichever is less. For lots 1 acre or larger: 75% of the main house habitable area OR 2,000 sq ft, whichever is less. Lot coverage standards of the zoning district also apply. Source: Tempe ADU page (tempe.gov/government/community-development/planning/accessory-dwelling-units-adus).

Sources & verification

Verified against official sources. Last reviewed 2026-06-29.

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

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