ADU Rules in Phoenix, AZ (2026)
ADU rules, permit requirements, size limits, and fees for Phoenix, AZ. Source-cited from official municipal code.
Whether ADUs are allowed in Phoenix, AZ has not been confirmed — see the official source before proceeding.
Whether Phoenix, AZ permits accessory dwelling units (ADUs) has not been confirmed from an official source. ADUs — also called granny flats, in-law units, or secondary suites — are secondary housing units on a single-family or multifamily lot. Contact the local building department at (602) 262-7811 to verify current ADU rules before proceeding, as regulations may have changed since this data was last reviewed.
ADU Size Limits
ADU Size Limits in Phoenix: Detached ADU: size varies by zoning — see official source (max height: varies — see official source). Attached ADU: size varies by zoning — see official source.
| Type | Max Size | Max Height |
|---|---|---|
| Detached ADU | See official source | See official source |
| Attached ADU | See official source | See official source |
Permit Fees
ADU Permit Fees in Phoenix: Plan check fee: Varies. Building permit fee: Varies. Impact fees: None. School fees: None or N/A. Total estimated permit cost: Varies.
| Fee Type | Amount |
|---|---|
| Plan Check | $250–$1,500 |
| Building Permit | Based on construction value — typically $800–$3,500 |
| Impact Fees | Phoenix impact fees vary — Transportation, Water, and Sewer development fees apply |
| School Fees | None |
| Total Estimate | See official source |
Permit Timeline
Phoenix ADU Permit Timeline: Permit timeline has not been confirmed — contact the department for current processing times. Apply through the local building department online permit portal. Phone: (602) 262-7811.
Setback Requirements
ADU Setback Requirements in Phoenix: Front setback: follows zone standard. Side setback: no minimum. Rear setback: no minimum.
Parking Requirements
Parking Requirements: Parking requirements have not been confirmed — see official source.
Restrictions & Requirements
- ADU must be on same lot as primary single-family dwelling
- Maximum size: 50% of primary dwelling floor area or 1,200 sqft
- One ADU per single-family residential lot
- ADU must meet Phoenix building code and zoning standards
- Corner lots may have additional setback requirements from street-facing yards
- Impervious surface and lot coverage limits still apply per zone
How Many ADUs Are Allowed?
Number of ADUs Allowed in Phoenix: Single-family lots: not confirmed — see official source. Multifamily properties: not confirmed — see official source.
- Single-Family Lots
- 1 ADU per single-family lot
- Multifamily Properties
- ADUs allowed in some multifamily zones per PDD review
Statewide Preemption
ADU Preemption
Arizona state law preempts local ADU rules — local governments cannot impose stricter standards.
View Arizona preemption detailsState Law & Preemption
State Preemption: AZ state law preempts local ADU restrictions. Phoenix must approve compliant ADU applications by right.
Frequently Asked Questions
Can I build an ADU in Phoenix?
Yes. Phoenix, AZ allows accessory dwelling units. On a single-family lot you can build 1 ADU per single-family lot.
How big can an ADU be in Phoenix?
The maximum size for a detached ADU in Phoenix is 50% of primary dwelling floor area or 1,200 sqft, whichever is less square feet.
How long does it take to get an ADU permit in Phoenix?
The typical ADU permit timeline in Phoenix is Phoenix PDD building permit: typically 3-6 weeks for residential additions. Electronic plan review available via Phoenix ePermits portal. Construction typically 3-9 months.. Total estimated permit fees are $2,000–$10,000 total fees including development fees.
Do I need extra parking for an ADU in Phoenix?
Phoenix parking rules for ADUs: No additional parking space required for an ADU under Arizona HB 2297. Phoenix cannot require additional off-street parking spaces for an ADU as a condition of approval.
Do I have to live on-site to have an ADU in Phoenix?
Owner-occupancy requirement in Phoenix: No owner-occupancy requirement under Arizona HB 2297. Phoenix removed its previous owner-occupancy requirement from its local ADU ordinance in 2024 to comply with state law.
Source: Phoenix Zoning Ordinance Section 606 — Accessory Dwelling Units; Arizona HB 2297 (Laws 2024, Chapter 204). Last verified April 5, 2026. View source