Zoning & Size Limits
| Requirement | Austin, TX | Houston, TX |
|---|
| Allowed Zones | SF3, SF2, SF1, MU, UR, etc. | Houston has no zoning code — ADUs are governed by deed restr |
| 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. | 900 sq ft (typical city standard; verify against deed restrictions and any 1,000 sq ft / 50%-of-primary limits) |
| Max Size (Attached) | Lesser of 1,100 sq ft or 15% of lot area (HOME Initiative) | 900 sq ft |
| Max Height | 30 feet (2 stories typical under HOME) | Confirm with City of Houston Planning — governed b |
| Parking Required | No off-street parking required for ADUs under 550 sq ft; 1 s | 1 off-street parking space required for ADU (separate from p |
| Owner Occupancy | Not required | Not required by the city (no citywide owner-occupancy mandat |
Setback Requirements
| Setback | Austin, TX | Houston, TX |
|---|
| Rear Setback | 10 feet | 5 feet |
| Side Setback | 5 feet | 5 feet |
| Front Setback | 25 feet | Confirm with City of Houston (front setback varies |
Permits & Timeline
| Detail | Austin, TX | Houston, TX |
|---|
| Permit Timeline | Confirm with Austin Development Services Department (typical 45-90 days) | 60-90 days |
| Permit Fees | $2,500-$4,000 | $3,000-$5,500 |
| Impact Fees | $1,200-$2,000 | $800-$1,500 |
| Pre-Approved Plans | City offers expedited review for pre-approved plan | Limited pre-approval program |
Construction Costs
| Cost | Austin, TX | Houston, TX |
|---|
| Avg Build Cost | $125,000-$250,000 | $120,000-$240,000 |
| Cost Per Sq Ft | $165-$330 | $100-$200 |
| Garage Conversion | $60,000-$140,000 | $50,000-$130,000 |
| Prefab ADU | $85,000-$200,000 | $80,000-$190,000 |
Rental Income Potential
| Rental | Austin, TX | Houston, TX |
|---|
| 1BR Avg Rent | $1,300-$1,900/mo | $1,100-$1,600/mo |
| 2BR Avg Rent | $1,700-$2,500/mo | $1,400-$2,100/mo |
| Short-Term Rentals | Check local restrictions | Varies by neighborhood |
| Est. ROI | 7-10% annual return | 6-9% annual return |
Which City Is Better for ADUs?
Austin scores 8/10 while Houston scores 6/10 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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