Yavapai County, AZ Accessory Structures: ADU Rules (2026)

Section 537 of the county zoning ordinance treats ADUs as a permitted use, not a conditional or discretionary one, wherever a single-family dwelling is already allowed, and the property keeps its single-family status even after an ADU is added; ADUs don't trigger the multi-family standards in Section 414's R2 District.

Size and count are fixed by formula. One attached and one detached ADU are allowed per lot, each capped at 1,000 square feet of interior habitable area. A lot of one acre or more gets a second detached ADU allowance, capped at 1,500 square feet. Height follows whatever limit applies to the primary single-family dwelling in that zoning district (Section 540). Setbacks are lighter than the main house: the front yard must match the district's single-family front setback, but the rear, interior side, and exterior side setbacks only need five feet, and an ADU can't sit on a platted public utility easement without the utility's written consent.

Construction doesn't have to match the main house's design, roof pitch, or materials, but it must meet the county's adopted Building Codes, and any ADU not tied into an adequate sewer system needs its own properly sized onsite wastewater system before construction. No extra parking is required for an ADU itself, though removing required parking for the main residence means replacing those spaces where the Development Services Director allows. Yavapai County's Addressing Unit assigns each ADU its own address, posted at the driveway entrance and on the structure in at least 4-inch reflective numbers.