Everything homeowners ask about building an ADU in Scottsdale — answered with 2026 data.
Yes, ADUs are allowed in Any single-family residential lot that already has a main single-family house (ZO Sec. 7.900, Ord. 4687); the city's ADU FAQ says such lots can be in single-family or multifamily residential districts but not commercial districts. ARS 9-461.18(G) excludes tribal land and lots inside the 65 dB noise contour of Scottsdale Airport or Sky Harbor (HB 2928 shrank those areas in 2025). In the ESL overlay an ADU may not be built inside required NAOS. HOA CC&Rs still apply. in Scottsdale, AZ. The maximum size for a detached ADU is First ADU on the lot: 1,000 sq ft or 75% of the existing main house, whichever is less (Sec. 7.900; ARS 9-461.18 measures interior habitable area). The second and any third ADU: 500 sq ft each. Every ADU needs a private outdoor living space at least 5 ft deep and 50 sq ft, and no more than 6 adults may live in the house and ADUs combined. Attached ADUs can be up to Same cap as detached: 1,000 sq ft or 75% of the main house for the first ADU, 500 sq ft if it is the second unit. Scottsdale has an ADU-friendliness score of 6/10. Check our full Scottsdale ADU rules page for complete zoning details.
ADU construction in Scottsdale typically costs $160,000-$320,000. The cost per square foot averages $200-$400. Garage conversions are more affordable at $80,000-$165,000, while prefab ADUs cost $155,000-$300,000. Permit fees add FY2026/27 schedule (Res. 13661, from July 1, 2026): pre-application $131, ADU staff-approval review $131, permit $237 base plus $0.94/sq ft livable and $0.54/sq ft covered, plan review $0.54 and $0.34/sq ft, CO $195, GIS $379: about $1,800 for 500 sq ft, $2,550 for 1,000 sq ft. to your budget. See our detailed Scottsdale ADU cost guide.
Detached ADUs in Scottsdale can be up to First ADU on the lot: 1,000 sq ft or 75% of the existing main house, whichever is less. Attached ADUs are limited to Same cap as detached: 1,000 sq ft or 75% of the main house for the first ADU, 500 sq ft if it is the second unit. Junior ADUs (JADUs) have a cap of Scottsdale has no junior ADU category. A unit carved out of the house is an attached ADU with the same 1,000 sq ft / 75% cap, its own exterior entrance and separate electric and gas meters. An existing guest house can become an ADU if it meets Sec. 7.900 and receives administrative approval; no earlier unpermitted unit is grandfathered (city ADU FAQ, Oct 2025). Maximum height is Same maximum height as the underlying zoning district allows for the main house (Sec. 7.900; ARS 9-461.18(B)(5) bars a stricter ADU limit). Limits differ between Scottsdale's R1 districts and the ESL and Foothills overlays, so confirm your lot's district limit at the pre-application meeting before design. You are allowed up to One attached plus one detached ADU per single-family lot; a third, detached ADU is allowed on a lot of 1 acre or more if at least one ADU is restricted-affordable on a qualifying lot.
Rear setback: 5 ft for a detached ADU built in the rear yard as the Zoning Ordinance defines it (Sec. 7.900; ARS 9-461.18(B)(6) caps ADU side and rear setbacks at 5 ft). An attached ADU keeps the main house's district rear setback. A detached ADU must also sit at least 10 ft from the main house and from any other ADU on the lot. Side setback: 5 ft for a detached ADU that is in the rear yard; a detached ADU may not be placed in a required side yard (Sec. 7.900). An attached ADU follows the district side setback for the house. On a corner lot the required front yard on the longer street frontage counts as a front yard, so a detached ADU cannot go there either. Front setback: Per the underlying district; a detached or restricted-affordable detached ADU may not be built in a required front yard, including the front yard on the longer street frontage of a corner lot (Sec. 7.900). A path of travel from each ADU to the lot's main street frontage is required. Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
No added parking for the ADU; the parking required for the main house must be maintained at all times (Sec. 7.900). ARS 9-461.18(B)(3) bars the city from requiring extra spaces or an in-lieu fee. A garage conversion therefore has to keep the house's required spaces elsewhere on the lot; confirm the replacement layout at the pre-application meeting. Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.
Not required for a long-term rental: the house and the ADU may be leased separately for 90 days or month-to-month (ARS 9-461.18(B)(1)-(2)). The owner must reside on the premises if the house or any ADU is rented or offered as a vacation or short-term rental (Sec. 7.900 and 7.203; authority ARS 9-500.39(B)(9)). An ADU cannot be sold separately or split off by subdivision or condominium plat. Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.
The ADU permit review timeline in Scottsdale is typically No ADU-specific figure is published. Residential Plan Review targets 7 business days for the administrative completeness check and 15 business days for substantive review per cycle; the pre-application meeting is usually scheduled within a week. Allow for at least one correction cycle. Plan check: Full residential plan review in SPUR: an administrative completeness check (7 business days), then substantive review by Planning, Building, Engineering, Stormwater and Fire (15 business days); corrections restart the cycle. Fees are charged on both conditioned and covered square footage, and grading/drainage sheets are priced per sheet by landform. ESL lots add NAOS, native-plant and wash review; a lot in a special flood hazard area needs a $363 lowest-floor certificate review. State law bars a fire-sprinkler or commercial-code requirement for an ADU (ARS 9-461.18(D)). Pre-approved plans availability: None posted. As of September 2026 the city's ADU page and fee schedules list no pre-approved ADU plan set (the 'Single Family Standard Plan' fee line is for production-builder repeats). ARS 9-461.20 (SB 1529 of 2025) requires every Arizona city to offer at least three pre-approved ADU plans at 200, 600 and 1,000 sq ft from July 1, 2026 and to accept outside submissions, so ask the One Stop Shop (480-312-7725) whether Scottsdale's are available.
Average ADU rental income in Scottsdale: 1-bedroom units rent for $1,650-$2,250/month, 2-bedroom units for $1,950-$2,600/month. Short-term rentals: Yes, with a Scottsdale short-term rental license for the property (Ordinance 4566; state law caps the fee at $250) and only if the owner physically resides on the property: Sec. Expected ROI: Roughly 6-10% gross rental yield on a $160,000-$320,000 detached build at $1,700-$2,200/mo, before taxes, vacancy, insurance and financing.
The minimum lot size for an ADU in Scottsdale is None: any single-family lot with an existing main house qualifies, and ARS 9-461.18(B)(5) bars lot-size, coverage or frontage rules stricter than the district applies to the house. Lot size matters only for a third ADU (1 acre or more) and on ESL lots, where the NAOS set-aside of 20-80% of the lot by slope shrinks the buildable area. This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.
Garage conversions are one of the most popular and affordable ADU options. In Scottsdale, a garage conversion typically costs $80,000-$165,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.
Tell us about your project and we'll pass it to ADU builders serving Scottsdale. Free, no obligation — you choose who to work with. We don't have builders in every area yet; if nobody covers yours, we'll email you to say so.
🔒 Your info is secure. We share it only with contractors quoting your project. No spam, no obligation.
Just browsing? Search ADU builders near you by ZIP code.