Accessory Structures in Maricopa County, AZ (2026)

5 county-level rules, plus city-specific rules for 10 cities in Maricopa County, Arizona.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Maricopa County. If you live within an incorporated city, that city's own rules apply — see the city list below.

ADU Rules

Arizona HB 2570 (2021) requires counties to allow ADUs on single-family lots. Maricopa County cannot ban ADUs, require owner-occupancy, or mandate additional parking. The county allows attached and detached ADUs with development standards including setbacks, lot coverage, and height limits. The updated 2026 zoning ordinance includes an 18-foot height cap for ADUs encroaching into setbacks and 30% side-yard coverage cap.

Accessory Structures: Adu Rules

Some Restrictions

Full ordinance details →Official source ↗

Shed Rules

Detached accessory buildings (sheds) in unincorporated Maricopa County may be built in required rear and side yards but cannot occupy more than 30% of any required yard. Sheds must be at least 3 feet from side and rear lot lines. They are prohibited in required front yards. Building permits are required. Maximum height is 30 feet in rural and single-family residential zones.

Accessory Structures: Shed Rules

Some Restrictions

Full ordinance details →Official source ↗

Garage Conversions

Garage conversions to living space in unincorporated Maricopa County require building permits and must meet residential building code standards for habitable space including insulation, egress windows, electrical, and plumbing. Converted garages may qualify as ADUs under state law. Replacement parking may not be required per HB 2570 ADU provisions.

Accessory Structures: Garage Conversions

Some Restrictions

Full ordinance details →Official source ↗

Carport Rules

Carports in unincorporated Maricopa County are regulated as accessory structures. They may be built in required rear and side yards but cannot occupy more than 30% of the required yard and must be at least 3 feet from side and rear lot lines. Building permits are required. Carports in front yards are generally prohibited unless the zoning district allows covered parking in front setbacks.

Accessory Structures: Carport Rules

Some Restrictions

Full ordinance details →Official source ↗

Tiny Homes

Tiny homes in unincorporated Maricopa County are regulated as either ADUs or manufactured/mobile homes depending on their construction. Site-built tiny homes on permanent foundations may qualify as ADUs under HB 2570 (ARS 9-462.01(U)). Tiny homes on wheels are classified as recreational vehicles and cannot serve as permanent dwellings. Building permits and compliance with residential building codes are required.