Zoning & Size Limits
| Requirement | Dallas, TX | San Antonio, TX |
|---|
| Allowed Zones | Single-family residential — but ADUs are generally NOT by-ri | Permitted by right (subject to use-specific standards) in mo |
| Max Size (Detached) | 800 sq ft (Dallas caps ADUs at 800 sq ft) | 800 sq ft (1,200 sq ft in the RE zone) per UDC §35-371 |
| Max Size (Attached) | Greater of 700 sq ft or 25% of the main dwelling's floor area (Dallas City Code §51A-4.510) | Up to 35% of the principal dwelling's living area (UDC §35-371) |
| Max Height | 35 feet | Generally may not exceed the height of the primary |
| Parking Required | Confirm with Dallas Planning & Development — an additional o | One on-site space required only if the ADU exceeds 800 sq ft |
| Owner Occupancy | Required — either the primary dwelling or the ADU must be ow | Required — owner must occupy either the principal unit or th |
Setback Requirements
| Setback | Dallas, TX | San Antonio, TX |
|---|
| Rear Setback | 15 feet | 5 feet (detached ADU may be 3 ft or more from side and rear lines per UDC §35-371) |
| Side Setback | 5 feet | 5 feet |
| Front Setback | 20 feet | 25 feet |
Permits & Timeline
| Detail | Dallas, TX | San Antonio, TX |
|---|
| Permit Timeline | 50-75 days | 90-120 days |
| Permit Fees | $2,200-$3,800 | $4,000-$6,500 |
| Impact Fees | $900-$1,600 | $1,200-$2,200 |
| Pre-Approved Plans | Available for detached ADUs | Not available |
Construction Costs
| Cost | Dallas, TX | San Antonio, TX |
|---|
| Avg Build Cost | $115,000-$230,000 | $110,000-$220,000 |
| Cost Per Sq Ft | $130-$250 | $140-$275 |
| Garage Conversion | $55,000-$135,000 | $50,000-$130,000 |
| Prefab ADU | $80,000-$185,000 | $75,000-$170,000 |
Rental Income Potential
| Rental | Dallas, TX | San Antonio, TX |
|---|
| 1BR Avg Rent | $1,150-$1,700/mo | $1,050-$1,550/mo |
| 2BR Avg Rent | $1,450-$2,200/mo | $1,300-$1,950/mo |
| Short-Term Rentals | Not permitted in most areas | Not permitted |
| Est. ROI | 6-8% annual return | 5-7% annual return |
Which City Is Better for ADUs?
Dallas scores 6/10 while San Antonio scores 5/10 on our ADU-friendliness index.
Dallas edges ahead overall. Both cities offer viable ADU development opportunities — the best choice depends on your specific property, budget, and goals.
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