How Phoenix Handles Accessory Structures: A Practical Guide

Phoenix maintains 159 local ordinances across all categories, and 4 of those deal specifically with accessory structures. Here is a breakdown of what the city actually requires, what is prohibited, and where Phoenix falls on the strict-to-permissive spectrum compared to other cities.

Shed & Carport Rules

In Phoenix, one-story detached tool and storage sheds, playhouses and similar uses do not require a building permit if their aggregate floor area does not exceed 200 square feet, per Phoenix Building Construction Code Section 105.2.1. Sheds must still meet zoning setbacks of at least 3 feet from a side or rear property line under Zoning Ordinance Section 706.B.

Key details: Permit-exempt size: 200 sq ft or less, one story. Side/rear setback: 3 ft minimum. Front yard: Not permitted (use permit required between dwelling and front line). Max height: 8 ft within 5 ft of street side; 15 ft elsewhere in yard. Code Section: PBCC 105.2.1(1); Zoning Ordinance 706.B.

Erecting a shed that exceeds the 200 sq ft permit-exemption without a permit, or that violates zoning setbacks/height limits, is a code violation. The Planning and Development Department may require a permit be obtained or the structure relocated or removed; continued non-compliance is enforced through notices of violation and civil penalties under the Phoenix City Code.

Phoenix is more permissive than most cities when it comes to shed & carport rules. That said, there are still limits.

ADU Owner Occupancy

Phoenix requires a notarized owner-occupancy attestation before renting a short-term rental in an accessory dwelling unit whose certificate of occupancy issued on or after September 14, 2024.

Key details: Trigger: ADU C of O on/after 9/14/2024. Requirement: Notarized owner-occupancy attestation. Filed with: Planning and Development Department. Governing section: City Code § 10-197.A.11. Applies to: Short-term rental permit applicants only.

Applying for an STR permit for a qualifying ADU without the notarized owner-occupancy attestation results in a denied or incomplete application; renting without a valid permit exposes the owner to civil sanctions up to $3,500 per violation.

ADU Rules

Phoenix permits up to two accessory dwelling units (one attached, one detached) on a single-family detached lot, with a third allowed on lots of one acre or more when one ADU is affordable housing. A detached ADU may sit as close as 5 feet from a street side property line and 3 feet from an interior side or rear line under Zoning Ordinance Section 706.A.

Key details: ADUs per lot: 2 (1 attached + 1 detached); 3rd on 1-acre affordable lots. Detached ADU setback: 5 ft street side / 3 ft interior side or rear. Max height in required yard: 15 ft (use permit for more). Max size: 75% of primary dwelling, max 1,000 sq ft (small lots). Code Section: Zoning Ordinance Sec. 706.A; A.R.S. 9-461.18.

Constructing an ADU without required permits or outside the Section 706.A standards is a zoning and building-code violation enforced by the Planning and Development Department and Neighborhood Services. The city may issue a stop-work order or notice of violation and require correction; uncorrected violations can lead to civil code-enforcement action under the Phoenix City Code.

Phoenix is more permissive than most cities when it comes to adu rules. That said, there are still limits.

Garage Conversions

Phoenix allows converting an existing garage or carport into an Accessory Dwelling Unit, but the conversion must establish new equivalent off-street parking elsewhere on the lot in dustproof condition, and that replacement parking may not be placed in the front-yard setback. A converted garage ADU is regulated under Zoning Ordinance Section 706.A and requires building permits.

Key details: Garage conversion to ADU: Allowed (attached or detached). Replacement parking: Required, dustproof, not in front setback. ADU size cap: 75% of primary dwelling, max 1,000 sq ft (small lots). Permit: Construction permit + 2 sets of plans. Code Section: Zoning Ordinance 706.A; A.R.S. 9-461.18.

Converting a garage to living space without permits, or failing to provide compliant replacement parking, is a zoning and building-code violation. The Planning and Development Department may deny final approval, issue a notice of violation, and require permits or restoration of parking; persistent violations are subject to code-enforcement penalties under the Phoenix City Code.

The Bottom Line

Compared to many U.S. cities, Phoenix gives residents more room on accessory structures. 2 of the 4 rules here are rated permissive. But permissive does not mean unregulated. There are still requirements, and the city does enforce them when violations are reported.

Keep in mind that Phoenix can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.