Can you build a casita in Scottsdale? In most cases, yes. Since the City Council adopted Ordinance 4687 on Sept. 30, 2025, Scottsdale allows one attached and one detached accessory dwelling unit (ADU) on a single-family lot that already has a main home. The first ADU can be up to 1,000 square feet or 75% of the main house, whichever is less.
What's the catch? An ADU is a true second home on your lot, so it must have its own kitchen and bathroom, a separate entrance, its own address and separately metered electric service, and it goes through a pre-application and administrative review before you can pull building permits. A traditional guest house is still an option, with different rules.
Data note: Rules below come from the City of Scottsdale's ADU page (last updated May 21, 2026), the city's ADU FAQ, Ordinance 4687 and A.R.S. 9-461.18. This is general information, not legal or zoning advice for a specific parcel.
ADU vs. Guest House: Which One Are You Building?
Scottsdale's zoning ordinance treats these as two different land uses. The city's own comparison:
Accessory Dwelling Unit (ADU)
- Can be rented separately from the main home
- Attached or detached
- Up to 1 attached + 1 detached (plus a restricted-affordable unit on qualifying lots of one acre or more)
- Size: 75% of the main home or 1,000 sq. ft., whichever is less; any additional ADU tops out at 500 sq. ft.
- Utilities: separately metered
- Approval: administrative review, then construction permits
Guest House
- Cannot be rented separately from the main home
- Detached only
- No set number, limited by size: up to 50% of the main home cumulatively
- Utilities: shared with the main home
- Deed restriction required
- Approval: construction plans for permitting
If you want a space for visiting family or a home office and never plan to rent it, a guest house may be simpler. If flexibility and future rental use matter, the ADU path is built for that.
Scottsdale ADU Requirements at a Glance
Size and Placement
- First ADU: the lesser of 1,000 sq. ft. or 75% of the main home
- Second (or third) ADU: 500 sq. ft. maximum
- Height: no taller than the underlying zoning district allows
- Attached ADUs follow the main home's setbacks
- Detached ADUs can't go in a required front or side yard; in the rear yard they may sit as close as 5 feet to a side or rear lot line
- Separation: at least 10 feet from the main house and from any other ADU
Livability and Access
- Private outdoor space for each ADU: at least 5 feet deep and 50 sq. ft.
- Separate exterior entrance and a path to the main street frontage
- Unique address displayed near the ADU entrance
- Parking for the main home must be maintained
- Occupancy cap: no more than six adults in total across the main home and all ADUs
Ownership and Utilities
- An ADU can't be sold separately, and the lot can't be split to create one
- Separately metered electric and gas; water and sewer use the existing public tap, then branch to separate connections on private property
- Older, unpermitted units are not grandfathered. Per the city FAQ, they must meet the new rules and be approved before operating legally as an ADU
How the Scottsdale ADU Permit Process Works
- Pre-application online: share a site plan, elevations and utility details if you have them
- Pre-application meeting with city staff to review requirements
- Formal administrative application for review and approval
- Construction documents and permit review, then a building permit once code requirements are met
Two state-law guardrails help homeowners here. Under A.R.S. 9-461.18, cities can't require extra parking for an ADU, can't force it to match the main home's roof pitch or materials, and can't require fire sprinklers or a commercial building code. ADUs also can't be built on a public utility easement without the utility's written consent, so check your plat early.
What an ADU Means for 85250 Homes
If your 85250 home is a single-family house on its own lot, the ordinance likely applies to you. Before you sketch anything:
- Check your HOA. State law expressly allows private restrictive covenants on ADUs, so CC&Rs may still limit them
- Check airport overlays. The city notes parts of Scottsdale fall within the operating vicinity of Phoenix Sky Harbor and Scottsdale Airport, where ADU limits can apply
- Think resale. A permitted, separately metered casita is easier to market and appraise than a converted garage with an extension cord
If you're weighing a pool or yard project alongside a casita, our guide to Scottsdale pool fence requirements covers another permit-sensitive item buyers ask about.
“When I show a Chaparral Park home with a permitted casita, buyers immediately start imagining uses: a parent's suite, a studio, a long-term rental. What they ask next is whether it's legal. If you're planning one, build it through the city's ADU process and keep every approval in a folder. That paperwork becomes part of your listing story.”
— Elizabeth Vijan, Tackett Team, eXp Realty
FAQ: Building a Casita or ADU in Scottsdale
Can I build a casita in my backyard in Scottsdale?
Usually, yes. Scottsdale allows one attached and one detached ADU on a single-family lot with an existing main home.
How big can an ADU be in Scottsdale?
The first ADU is capped at 1,000 sq. ft. or 75% of the main home, whichever is less. A second is capped at 500 sq. ft.
Can I rent out my casita in Scottsdale?
An ADU can be rented separately; a guest house can't. The city says the owner must live on site for a rented ADU or a short-term rental.
Can my HOA stop me from building an ADU?
Possibly. A.R.S. 9-461.18 leaves private CC&R restrictions in place, so check your HOA documents first.
Thinking About a Casita Before You Buy or Sell in 85250?
I can help you find homes with room for an ADU, review permit history on an existing casita, or position yours so buyers see the value.
Elizabeth Vijan | Tackett Team, eXp Realty
Chaparral Park Resident & 85250 Real Estate Expert
Talk to Elizabeth About Your Plans · Call or text 602-885-7752
Sources: City of Scottsdale: Accessory Dwelling Units (ADUs) · City of Scottsdale: ADU FAQ (PDF) · City of Scottsdale: Planning legislative updates · Arizona Revised Statutes 9-461.18: Accessory dwelling units
Disclaimer: General information, not legal, zoning or tax advice. Requirements can change and vary by parcel, zoning district and HOA. Confirm with City of Scottsdale Planning & Development before designing or building. Information deemed reliable but not guaranteed. Equal Housing Opportunity.
