Zoning & Size Limits
| Requirement | Austin, TX | Fort Worth, TX |
|---|
| Allowed Zones | SF3, SF2, SF1, MU, UR, etc. | One-family residential districts ('A-5', 'A-7.5', 'A-10', 'A |
| Max Size (Detached) | Lesser of 1,100 sq ft or 15% of lot area (HOME Initiative). 2nd-story floor area capped at 550 sq ft. | 1,000 sq ft |
| Max Size (Attached) | Lesser of 1,100 sq ft or 15% of lot area (HOME Initiative) | Limited by the district's floor-area and lot-coverage rules |
| Max Height | 30 feet (2 stories typical under HOME) | May not exceed the height of the primary residence |
| Parking Required | No off-street parking required for ADUs under 550 sq ft; 1 s | Off-street parking per district standards (confirm with Deve |
| Owner Occupancy | Not required | Effectively required — an ADU may not be a separate independ |
Setback Requirements
| Setback | Austin, TX | Fort Worth, TX |
|---|
| Rear Setback | 10 feet | Must meet the rear setback of the underlying district (commonly 5–10 ft for accessory structures) |
| Side Setback | 5 feet | Must meet the side setback of the underlying district (commonly 5 ft) |
| Front Setback | 25 feet | Must be behind the front building line of the prim |
Permits & Timeline
| Detail | Austin, TX | Fort Worth, TX |
|---|
| Permit Timeline | Confirm with Austin Development Services Department (typical 45-90 days) | About 4–9 weeks from complete application to permit issuance (confirm current queue with Development Services) |
| Permit Fees | $2,500-$4,000 | $2,400-$4,000 (building permit + plan review; varies with valuation and square footage) |
| Impact Fees | $1,200-$2,000 | $1,000-$1,800 typical water/sewer connection charges (confir |
| Pre-Approved Plans | City offers expedited review for pre-approved plan | No formal pre-approved ADU plan set; standard plan |
Construction Costs
| Cost | Austin, TX | Fort Worth, TX |
|---|
| Avg Build Cost | $125,000-$250,000 | $120,000-$240,000 |
| Cost Per Sq Ft | $165-$330 | $120-$240 |
| Garage Conversion | $60,000-$140,000 | $55,000-$135,000 |
| Prefab ADU | $85,000-$200,000 | $85,000-$195,000 |
Rental Income Potential
| Rental | Austin, TX | Fort Worth, TX |
|---|
| 1BR Avg Rent | $1,300-$1,900/mo | $1,100-$1,650/mo |
| 2BR Avg Rent | $1,700-$2,500/mo | $1,400-$2,100/mo |
| Short-Term Rentals | Check local restrictions | Restricted in most areas |
| Est. ROI | 7-10% annual return | 6-9% annual return |
Which City Is Better for ADUs?
Austin scores 8/10 while Fort Worth scores 5/10 on our ADU-friendliness index.
Austin 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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