ADU Design in Winslow, AZ

ADU Design in Arizona: what governs your project

Arizona adopted statewide ADU reform in 2024, requiring larger municipalities to allow at least one accessory dwelling unit by right on single-family lots. The law limits cities' ability to impose owner-occupancy mandates and certain design restrictions, though local development standards still apply.

Energy code

Permitting is ministerial in covered cities, with limits on impact fees for smaller units. Setback, height, and size standards vary by city, and utility hookup requirements are set locally.

Permitting & plan check

Phoenix, Tucson, Mesa, and other large Valley cities run high-volume electronic permitting systems built for rapid growth. Smaller towns often contract plan review to third-party firms. Arizona's fast-paced development market makes pre-submittal meetings and over-the-counter review options common in the major metros.

Good to know

• Arizona is cooling-dominant, with extreme summer heat driving mechanical design in Phoenix and Tucson.
• Monsoon-season microbursts govern wind design across much of the state.
• ADEQ administers the AZPDES program for construction stormwater.

Every discipline, one team