As of October 2026, Scottsdale allows one attached and one detached ADU on a single-family lot under Ordinance 4687, adopted September 30, 2025. The first ADU can reach 1,000 sq ft or 75% of the main home, whichever is less. Any second or third ADU is limited to 500 sq ft.
What standards does Scottsdale apply?
- Placement. A detached ADU cannot sit in the required front or side yard. In the rear yard it can come within 5 feet of a side or rear line.
- Separation. At least 10 feet from the main home and from another ADU.
- Height. The maximum of the underlying zoning district.
- Entrance and address. Each ADU needs its own exterior entrance and a unique, visible address.
- Outdoor space. A private area at least 5 feet deep and 50 sq ft.
- Utilities. Separately metered electric and gas connections.
- Occupancy. No more than six adults across the main home and ADUs.
- Parking. Parking for the main house must be kept at all times.
Can I rent a Scottsdale ADU?
Long-term, yes. As a vacation or short-term rental, only while the owner lives on the property, according to the city's FAQ. An ADU cannot be sold separately from the house, and the lot cannot be split to separate them. See the short-term rental guide.
What about North Scottsdale lots?
Natural Area Open Space (NAOS) still applies in the northern parts of the city, and an ADU cannot be built inside NAOS. On desert lots with large preserved areas, that often decides where the unit can go.
What if I already have a casita?
Scottsdale says older ADUs are not grandfathered; an existing unit must meet the new rules and be approved. A guest house can be converted to an ADU if it meets the standards. See casita, guest house or ADU.
Were there disputes over Scottsdale's rules?
Yes. Its first 2024 rules excluded much of the city near airports, and the bill's sponsor called that "egregious" in December 2024 coverage. The 2025 state amendment reduced those airport areas, and Scottsdale's 2025 update followed. We work from the ordinance in effect when you apply.