ADU Permits: Scottsdale vs Tempe
How do adu permits rules compare between Scottsdale, AZ and Tempe, AZ?
Scottsdale and Tempe have similar restriction levels.
Scottsdale, AZ
Maricopa County
Scottsdale permits accessory dwelling units by-right under Arizona Revised Statutes Sec. 9-461.18, enacted by HB 2720 in 2024 and effective January 1, 2025 for cities over 75,000 population. Scottsdale (population approximately 241,000) qualifies. The City of Scottsdale Zoning Ordinance was amended to comply. Single-family lots may have one detached and one attached ADU; lots over one acre may add a third detached ADU. Permits are issued through Planning & Development Services.
View full Scottsdale rules →Tempe, AZ
Maricopa County
Tempe permits accessory dwelling units by right on lots zoned for single-family use under Arizona Revised Statutes section 9-461.18, enacted by HB 2720 in 2024. Tempe (population approximately 185,000) is well over the 75,000 threshold that triggers the state by-right mandate. Tempe's Zoning and Development Code was amended to comply, allowing at least one attached and one detached ADU per single-family lot. Building permits issue through Tempe Community Development.
View full Tempe rules →Key Facts Comparison
| Fact | Scottsdale | Tempe |
|---|---|---|
| State Mandate | Ariz. Rev. Stat. 9-461.18 (HB 2720) | - |
| City Code | Scottsdale Zoning Ordinance (amended 2024) | Tempe ZDC + City Code Ch. 8 |
| Units Allowed | 1 detached + 1 attached (3 if 1+ acre) | 1 attached + 1 detached by right |
| Permit Authority | Scottsdale Planning & Dev Services | - |
| ESLO Constraints | Apply in north Scottsdale | - |
| By-Right Standard | Yes on single-family lots | - |
| State Law | - | ARS 9-461.18 (HB 2720) |
| Max Side/Rear Setback | - | 5 ft (state cap) |
| Population Threshold | - | Tempe ~185k qualifies (over 75k) |
| Review | - | Tempe Community Development |
Highlighted rows indicate differences between cities.
Scottsdale FAQ
Can I build an ADU in Scottsdale by-right?
Yes. Under Arizona HB 2720 (Ariz. Rev. Stat. Sec. 9-461.18), Scottsdale must allow one detached and one attached ADU by-right on every single-family lot. Lots over one acre may add a third detached unit. Building, plumbing, mechanical, and electrical permits through Planning & Development Services are still required.
Does the Environmentally Sensitive Lands Ordinance affect my ADU?
Yes if your lot is in the ESLO overlay (most of north Scottsdale). HB 2720 does not exempt ADUs from generally applicable slope, native-vegetation salvage, grading, and view-corridor requirements. Detached ADU placement and pad design must still comply with the ESLO.
Tempe FAQ
Can I build a casita in Tempe by right?
Yes. Under Arizona HB 2720 (ARS 9-461.18), Tempe must allow one attached and one detached ADU by right on any single-family lot. Discretionary use permits and public hearings are preempted. You still need building, electrical, plumbing, and mechanical permits through Tempe Community Development.
How close to my property line can the ADU sit in Tempe?
The state statute caps the side and rear yard setbacks Tempe can impose at no more than 5 feet. Tempe's Zoning and Development Code was updated to comply. Front yard setbacks follow the underlying single-family district standards.
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