Before You Build in Pima County, AZ: Permit & Rule Checklist (2026)

Pima County has no neighbor fence cost-sharing ordinance. Arizona law does not require neighbors to split fence costs. Owners may build on their own property up to zoning limits.

ARS 36-1681 requires 5-ft pool barriers with self-closing, self-latching gates in Pima County. Applies to all pools 18+ inches deep. Door alarms or safety covers as alternatives.

Pima County limits front yard fences to 3 ft (solid) or 4 ft (open). Side and rear fences up to 6 ft. Hillside development zones have stricter height and material rules.

Building permits required for retaining walls over 4 ft in Pima County. Licensed engineer must design walls exceeding 4 ft. Hillside zones require terracing and natural colors.

Block walls and masonry fences typically require building permits in Pima County. Wood fences under 6 feet may be exempt. Pool barriers must meet ARS §36-1681.

Hot tubs and spas in unincorporated Pima County must comply with ARS 36-1681 barrier requirements if they hold water deeper than 18 inches. A lockable safety cover meeting ASTM F1346 standards may substitute for a full barrier enclosure. Electrical work requires a county permit.

Pima County requires barrier fencing around all swimming pools, including above-ground pools, per ARS 36-1681 and county building code. Above-ground pools with walls 48 inches or higher may use the pool wall as the barrier if access points are secured. A building permit is generally required.

Pima County requires building permits for pools, spas, and hot tubs. Arizona has strict pool barrier requirements under ARS §36-1681. Inspections required.

ARS §36-1681 requires pool barriers - one of the strictest laws in the US. Minimum 5-foot barrier height. Self-closing, self-latching gates required.

Pima County enforces strict pool safety per ARS §36-1681 and the federal VGB Act. Anti-entrapment drains, barriers, alarms, and depth markers required.

Pima County allows accessory dwelling units (ADUs or guest houses) in certain residential zones subject to zoning code requirements. ADUs must be subordinate to the primary dwelling, meet setback and height limits, and comply with building code. ADUs built after September 14, 2024 and used as STRs require owner occupancy on the property.

Converting a garage to living space in unincorporated Pima County requires a building permit from Development Services. The conversion must meet residential building code for habitable space including insulation, ventilation, egress windows, and ceiling height. Replacement off-street parking may be required by the zoning code.

Pima County allows carports as accessory structures in residential zones. Open carports (roof only, no enclosed walls) under 200 square feet may be exempt from building permits. Larger carports require permits and must meet setback and wind-load requirements for the monsoon climate.

Pima County permits tiny homes as accessory dwelling units under the 2024 Zoning Code update for unincorporated areas. Tiny homes on wheels are classified as recreational vehicles and cannot serve as permanent dwellings. Site-built or modular tiny homes on foundations must meet IRC building standards and obtain standard building permits through Pima County Development Services.

Pima County allows storage sheds as accessory structures in all residential zones. Sheds under 200 square feet and not on a permanent foundation typically do not require a building permit. Larger sheds require permits and must meet setback requirements. All sheds must comply with wind and tie-down requirements for the Sonoran Desert climate.

Outdoor burning in unincorporated Pima County requires a PDEQ permit under ARS 49-501 and County Code 17.20. No-burn days declared during poor air quality periods.

Recreational fire pits for warmth and cooking are exempt from PDEQ open burn permit requirements in unincorporated Pima County. Gas/propane fire features always exempt. 25-foot clearance from structures recommended. PDEQ no-burn advisories apply to wood burning.

Tucson Water and the Arizona Department of Water Resources (ADWR) regulate water use in the Tucson Active Management Area, which covers most of Pima County. ADWR Assured Water Supply rules (ARS 45-454) require new subdivisions to demonstrate a 100-year water supply. Tucson Water enforces stage-based drought restrictions.

Saguaro removal requires state permits (ARS §3-904) throughout unincorporated Pima County. Native plant protections apply on development sites per county zoning code. Unauthorized saguaro removal is a Class 4 felony.

Pima County may protect native desert trees (palo verde, ironwood, saguaro). Street trees are city property. Proper pruning preserves shade in extreme heat.