ADU Regulations — Phoenix, AZ

Governed by Sec. 7.5.2(A). Last verified June 2, 2026.

All Areas

Requirement	Value	Conditions / Exceptions	Source
Allowed Types	Detached, attached, conversion of existing habitable space	—	Sec. 7.5.2(A)
Allowed Zones	R1-4, R1-5, R1-6, R1-7, R1-8, R1-9, R1-10, R1-12, R1-13, R1-14, R1-20	—	Sec. 7.5.2(A)
Max Height	20 feet	Not to exceed height limit of the primary structure if lower	Sec. 7.5.2(D)
Max Per Lot	1	—	Sec. 7.5.2(B)
Max Size	1000 sq ft or 50% of primary dwelling floor area, whichever is less	—	Sec. 7.5.2(C)
Owner Occupancy	Required	Owner must occupy either the primary dwelling or the ADU	Sec. 7.5.2(F)
Parking Required	1 space per ADU	Exception: No parking required if ADU is within 1/4 mile of a light rail station or a bus stop with 15-minute peak service	Sec. 7.5.2(E)
Permit Required	Yes	Building permit required	Sec. 7.5.2(G)

Official Code Language (8 sections)

ADUs may be detached, attached, or created through conversion of existing habitable space (Sec. 7.5.2(A)).

— Sec. 7.5.2(A)

ADUs are permitted in the following zoning districts: R1-4, R1-5, R1-6, R1-7, R1-8, R1-9, R1-10, R1-12, R1-13, R1-14, and R1-20 (Sec. 7.5.2(A)).

— Sec. 7.5.2(A)

The maximum height for an ADU is 20 feet (Sec. 7.5.2(D)).

— Sec. 7.5.2(D)

Only one ADU is allowed per lot (Sec. 7.5.2(B)).

— Sec. 7.5.2(B)

The maximum floor area of an ADU shall be 1,000 square feet or 50% of the primary dwelling's floor area, whichever is less (Sec. 7.5.2(C)).

— Sec. 7.5.2(C)

The property owner must occupy either the primary dwelling or the ADU (Sec. 7.5.2(F)).

— Sec. 7.5.2(F)

One off-street parking space is required for each ADU (Sec. 7.5.2(E)).

— Sec. 7.5.2(E)

A building permit is required for all ADUs (Sec. 7.5.2(G)).

— Sec. 7.5.2(G)

Permit Requirements

When required: All ADUs require a building permit
Where to apply: Phoenix Planning and Development Department

Documents needed:

Site plan
Floor plans
Proof of owner occupancy
Building permit application

Verified June 2, 2026

Permit Application Checklist

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Confirm permit is needed with the planning department
Site plan
Floor plans
Proof of owner occupancy
Building permit application
Submit to: Phoenix Planning and Development Department

Frequently Asked Questions

How big can my ADU be?

- The maximum size is 1,000 square feet. - It also cannot exceed 50% of your primary house's floor area. - For example, if your house is 1,500 sq ft, the ADU can be at most 750 sq ft (50% of 1,500), even though 1,000 sq ft is bigger. - Always use the smaller of the two limits.

Do I need to live on the property if I build an ADU?

- Yes, the property owner must occupy either the main house or the ADU. - You cannot rent out both units unless you live in one. - This is required by Sec. 7.5.2(F) regardless of zone.

How many ADUs can I build on my lot?

- Only one ADU is allowed per lot. - This is true for all zones where ADUs are permitted. - You cannot build multiple ADUs, even if the lot is large.

Do I need extra parking for the ADU?

- Yes, you must provide one off-street parking space for the ADU. - This is in addition to any parking required for the main house. - The space can be a driveway, garage, or a dedicated parking area on your property.

Sources

Data last verified: June 2, 2026

See how this works nationally: ADU Rules by State

This is an informational summary, not legal advice. Verify current requirements with Phoenix Planning Department .

Found an error? Report a correction to help keep this information accurate.