1. The question, as people ask it
"Can I build a casita in Scottsdale now?" — also asked as "Didn't Scottsdale ban ADUs near the airport?", "Did the state force Scottsdale to allow casitas?", and "Which Scottsdale ADU rules are current?"
2. The short answer
Scottsdale has had three different answers in under two years. The current one dates from September 30, 2025.
- September 14, 2024 — Effect on a Scottsdale lot: Arizona's ADU law, HB 2720, took effect (A.R.S. § 9-461.18). Cities over 75,000 had until January 1, 2025 to adopt complying rules.; : State floor set.
- November 25, 2024 — Effect on a Scottsdale lot: Scottsdale adopted Ordinance 4652 (case 4-TA-2024), creating Zoning Ordinance Secs. 7.900–7.904.; : ADUs allowed citywide, except on any land "in the territory in the vicinity of" a military airport or an FAA-licensed, general aviation, or public airport (Sec. 7.902.A.1.b, as adopted). No noise test.
- May 23, 2025 (effective September 26, 2025) — Effect on a Scottsdale lot: The Legislature passed HB 2928 (Laws 2025, ch. 217), which narrowed the civil-airport exclusion to land "that has a noise level of greater than sixty-five decibels" (A.R.S. § 9-461.18(G)(3)).; : The state exclusion shrank.
- September 30, 2025 — Effect on a Scottsdale lot: Scottsdale adopted Ordinance 4687 (case 4-TA-2024#2) "to comply with a state law (HB2928)."; : The city's own page: HB 2928 "reduced the size of those restriction areas and thus expanded areas in Scottsdale where ADUs can be built." Current rules.
If you were told "no" in early 2025 because of the airport, the answer may be different now. Ask the city to check your parcel against the current 65-decibel test.
3. Why you may have heard otherwise
"The Attorney General forced Scottsdale." We found no primary record of an Attorney General action on Scottsdale's ADU rules. The mechanism in the public record is legislative: HB 2928 changed the statute, and Scottsdale amended its ordinance to match.
"Scottsdale banned casitas." It did not. Ordinance 4652 allowed them on single-family lots citywide, with the airport-vicinity exclusion the 2024 statute itself contained. The dispute was about how large those airport areas were, not whether ADUs were legal.
"The rules are the same as Phoenix's." They are not. Scottsdale caps a second or third ADU at 500 square feet, requires separately metered utilities, and caps occupancy at six adults across all units on the lot. Phoenix has none of those three rules.
4. What the current rules say
From the City of Scottsdale ADU page (Ordinance 4687, Zoning Ordinance Sec. 7.900), last updated May 21, 2026:
- Three unit types: Attached ADU, Detached ADU, and Restricted-Affordable Detached ADU.
- How many: one attached and one detached per single-family lot; a third, restricted-affordable detached unit on a lot of one acre or more.
- Size: the first ADU up to 1,000 square feet or 75% of the main home, whichever is less; a second or third ADU no more than 500 square feet.
- Occupancy: "No more than six (6) adults in cumulative total may occupy the main single-family residential dwelling and any ADUs constructed on the same lot."
- Placement: a detached ADU "may not be constructed in a required front yard or side yard"; one built in the rear yard "may be constructed as close as five (5) feet to a side or rear yard"; ten feet between buildings; private outdoor living space "minimum of five (5) feet deep and fifty (50) square feet in area."
- Utilities and access: separately metered electric and gas; water and sewer branch on private property; separate exterior entrance and its own address.
- Ownership and rental: "The ADU cannot be sold separately from the main single-family residential dwelling"; "The property owner must reside on the premise for any ADU that is rented, leased, offered for rent or lease, or occupied as a Vacation Rental or Short-term Rental."
The rules Ordinance 4652 put in place in November 2024 already contained most of these standards. As codified through July 2025, Sec. 7.904 set the same one-attached-plus-one-detached count, the same 75%-or-1,000-square-foot first unit and 500-square-foot cap on others, the six-adult occupancy limit, the five-foot rear-yard rule, the ten-foot separation, and the outdoor-space minimum. The 2025 ordinance's visible change on the city's page is the airport exclusion.
5. What's still unsettled
- The current codified text of Sec. 7.900. Re-read September 4, 2026: Municode labels its June 10, 2026 version current but still displays Ordinance 4652 text and history rather than Ordinance 4687's revised airport language. Current requirements, including the airport and owner-residency language, are therefore cited here to the City's ADU page, last updated May 21, 2026, not to Municode.
- Owner residency versus state law. The pre-4687 code sent rented ADUs to Sec. 7.203 (the short-term rental section) rather than imposing a blanket residency rule. The city page now states residency is required for any rented ADU. How that squares with A.R.S. § 9-461.18(B)(1), which bars a city from prohibiting separate long-term rental of an ADU, is not answered in the sources we read.
- Which parcels sit above 65 decibels. Scottsdale Airport's noise contours are published by the airport, not in the zoning ordinance. Whether a given lot is inside is a parcel-level check.
- Applications to date. The city's October 6, 2025 release said Scottsdale had "received only one formal application for an ADU." We did not find a later count.
