Scottsdale, AZ Accessory Structures: ADU Rules (2026)

Sec. §§ 28-8461 and 28-8486. Sec. 904 then sets the dimensional standards. Density is capped at one Attached ADU and one Detached ADU per lot; lots at least one acre may add a Restricted-Affordable Detached ADU on top of that. Overall, a lot under an acre tops out at two total ADUs, while a lot of an acre or more tops out at three, one of which must be the Restricted-Affordable type. Size is capped so that only one ADU on the lot may reach 75 percent of the main home's gross floor area or 1,000 square feet, whichever is less; every other ADU on the same lot is held to 500 square feet or less.

Combined occupancy of the main house and all ADUs cannot exceed six adults, height cannot exceed the underlying zoning district's limit, and detached units cannot sit in a required front or side yard, though they may come within five feet of a side or rear line in a rear yard. Buildings must keep ten feet of separation from each other, each ADU needs its own five-foot-deep, 50-square-foot private outdoor space and a separate exterior entrance, and existing required parking for the main home cannot be reduced.

Sec. 903 routes every application through the Zoning Administrator, whose approval, conditional approval, or denial decision on the development application is final and not appealable.