ADU rules in Phoenix

An ADU may be attached or detached. Two ADUs are permitted per lot with no more than one single-family detached primary dwelling (a third if one ADU is affordable and the net lot is at least 43,560 sq ft). A detached ADU may sit in required rear/side yards with 3 ft interior side/rear and 5 ft street-side setbacks; max 15 ft height in required yards without a use permit.

Maximum of one attached ADU per lot; it must comply with the height and setback rules of the primary dwelling and be integrated into its design so the home does not read as a duplex (separate entry allowed).

A garage, attached shade structure, or attached carport built as part of a detached ADU does not count toward the ADU's gross floor area. Lot coverage limits of the zoning district still apply.

No owner-occupancy requirement appears in the ADU provisions (ZO 608.E.2 and 706.A), so an owner may live elsewhere and rent both units long term. State law also bars Phoenix from requiring a familial, marital, employment, or other preexisting relationship between the owner or occupant of the primary dwelling and the ADU occupant. The one exception is short-term rental: since April 3, 2026, an application for a short-term rental permit on a property with an ADU whose certificate of occupancy issued on or after September 14, 2024 must include a notarized attestation that the property owner will reside on the same property (City Code 10-197(A)(11)).

Section 702's residential parking standards attach to the primary dwelling unit and list no ADU line item. A.R.S. 9-461.18(B)(3) prohibits Phoenix from requiring additional parking (or in-lieu fees) to accommodate an ADU.

The Residential Districts Land Use Matrix (608.D) lists ADU as 'pc2' (permitted subject to condition 608.E.2, no use permit) in every residential district column. A Section 307 use permit is needed only for exceptions: a detached ADU taller than 15 ft within required rear/side yards, or one placed between the primary dwelling and the front property line. Standard building permits via the Shape Phoenix portal still apply. The city's ADU page describes an ADU Standard Plan Library of free pre-approved detached designs from its 2024 design competition, but as of September 27, 2026 all four listed plans are marked 'IN REVIEW' and not yet available.

The ADU sections of the Zoning Ordinance (608.E.2 and 706.A) set no minimum lease term, and A.R.S. 9-461.18(B)(1) forbids Phoenix from prohibiting separate long-term rental of the house or the ADU. Renting any unit for less than 30 days requires a short-term rental permit under City Code Chapter 10, Article XVI, with a separate application for each dwelling unit on a single-family property. Ordinance G-7495 (adopted March 4, 2026, effective April 3, 2026) added the state-authorized owner-residency condition: if the property has an ADU whose certificate of occupancy issued on or after September 14, 2024, the permit application must include a notarized attestation that the owner will reside on the same property. ADUs approved before that date are not subject to the attestation.