Zoning & Size Limits
| Requirement | Tucson, AZ | Scottsdale, AZ |
|---|
| Allowed Zones | Limited to select residential zones | Very limited residential zones |
| Max Size (Detached) | 75% of primary dwelling, up to 1,000 sq ft (minimum 650 sq ft guaranteed) | 1,000 sq ft or 75% of primary dwelling (whichever is less); 500 sq ft for second/third ADU |
| Max Size (Attached) | 75% of primary dwelling, up to 1,000 sq ft (minimum 650 sq ft guaranteed) | 1,000 sq ft or 75% of primary dwelling (whichever is less) |
| Max Height | 30 feet | 30 feet |
| Parking Required | No parking required (effective November 2024, AZ HB 2720) | No additional parking required (AZ HB 2720) |
| Owner Occupancy | May be required in some zones | Not required for long-term rental; required only if ADU used |
Setback Requirements
| Setback | Tucson, AZ | Scottsdale, AZ |
|---|
| Rear Setback | 20 feet | 25 feet |
| Side Setback | 5 feet | 5 feet |
| Front Setback | 25 feet | 30 feet |
Permits & Timeline
| Detail | Tucson, AZ | Scottsdale, AZ |
|---|
| Permit Timeline | 90-120 days | 120-180 days |
| Permit Fees | $3,500-$5,500 | $5,000-$8,000 |
| Impact Fees | $1,200-$2,000 | $2,000-$3,000 |
| Pre-Approved Plans | Not available | Not available |
Construction Costs
| Cost | Tucson, AZ | Scottsdale, AZ |
|---|
| Avg Build Cost | $110,000-$220,000 | $140,000-$280,000 |
| Cost Per Sq Ft | $145-$290 | $200-$400 |
| Garage Conversion | $55,000-$130,000 | $75,000-$170,000 |
| Prefab ADU | $80,000-$180,000 | $110,000-$240,000 |
Rental Income Potential
| Rental | Tucson, AZ | Scottsdale, AZ |
|---|
| 1BR Avg Rent | $1,100-$1,500/mo | $1,500-$2,000/mo |
| 2BR Avg Rent | $1,400-$1,900/mo | $1,900-$2,600/mo |
| Short-Term Rentals | Not permitted | Not permitted |
| Est. ROI | 6-8% annual return | 4-6% annual return |
Which City Is Better for ADUs?
Tucson scores 5/10 while Scottsdale scores 5/10 on our ADU-friendliness index.
Both cities offer viable ADU development opportunities — the best choice depends on your specific property, budget, and goals.
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