ADU Rules in San Antonio, Texas

Complete guide to building an Accessory Dwelling Unit in San Antonio — zoning, setbacks, permits, costs, and more.

Max Size: 800 sq ft Setbacks: 20 feet No Parking Required Verified: 2026-02-22
ADU Score: 5/10

San Antonio has limited ADU allowances, primarily in certain zoning districts. The city is less progressive on ADU regulations than Austin or Dallas, requiring careful site analysis to verify compatibility with local zoning.

Zoning & Size Requirements [1]

Allowed ZonesSelected residential zones only
Max Size (Detached)800 sq ft
Max Size (Attached)Not typically allowed
Max Size (JADU)Not allowed
Max Height30 feet
Max Units1 ADU per lot

Setback Requirements [1]

Rear Setback20 feet
Side Setback5 feet
Front Setback25 feet
Parking Required2 spaces
Owner OccupancyNot required
Min Lot Size7,500 sq ft

Permit Process & Fees

Approval ProcessConditional use permit required
Review Timeline90-120 days
Permit Fees$4,000-$6,500
Impact Fees$1,200-$2,200
Plan Check4-6 weeks
Pre-Approved PlansNot available

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Construction Costs [2][3]

Average Build Cost$110,000-$220,000
Cost per Sq Ft$140-$275
Garage Conversion$50,000-$130,000
Prefab ADU (Installed)$75,000-$170,000

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Rental Income Potential [4][5]

Avg Rent (1 Bedroom)$1,050-$1,550/mo
Avg Rent (2 Bedroom)$1,300-$1,950/mo
Short-Term RentalNot permitted
Est. Annual ROI5-7% annual return

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Recent Law Changes

What's Changed Recently

  • Austin ADU ordinance expansion (2026): Larger units allowed on smaller lots
  • Houston no-zoning ADU policy updated: Streamlined permitting for garage conversions
  • San Antonio ADU pilot program results: 200+ permits issued, program made permanent
  • Texas legislature considering statewide ADU preemption bill (HB 2345) for 2026

Tips for Building an ADU in San Antonio

  • San Antonio requires conditional use permits; factor 90+ day timeline into plans
  • Verify your specific zoning district; many zones don't allow ADUs
  • Neighborhood compatibility considerations are heavily weighted in approval
  • Strong rental market in central areas; location matters significantly for ROI

Sources & References

All data on this page is sourced from official government records and verified market data. View our full methodology.

  1. ADU Permits — City of San Antonio Planning Department — Accessed 2026-02-24
  2. HomeAdvisor — ADU Construction Cost Data Market Data — Accessed 2026-02-24
  3. Angi — Local ADU Contractor Costs Market Data — Accessed 2026-02-24
  4. Zillow Rental Manager — Market Rent Data Market Data — Accessed 2026-02-24
  5. HUD Fair Market Rents Government Data — Accessed 2026-02-24
  6. San Antonio UDC § 35-371 — Accessory Dwellings Municipal Code — Accessed 2026-02-24
  7. Texas Local Government Code — Land Use Regulations Government Data — Accessed 2026-02-24

Frequently Asked Questions

Can I build an ADU in San Antonio?

Yes. ADUs are allowed in Selected residential zones only in San Antonio. The maximum size for a detached ADU is 800 sq ft. No owner-occupancy is required.

How much does an ADU cost in San Antonio?

ADU construction in San Antonio typically costs $110,000-$220,000. Garage conversions run $50,000-$130,000, and prefab ADUs cost $75,000-$170,000.

How much can I rent an ADU for in San Antonio?

Average ADU rents in San Antonio are $1,050-$1,550/mo for a 1-bedroom and $1,300-$1,950/mo for a 2-bedroom unit.

Do I need parking for an ADU in San Antonio?

2 spaces. Check with San Antonio planning department for the latest Texas ADU parking rules, as many states have relaxed requirements in recent years.

How long does it take to get an ADU permit in San Antonio?

The permit review timeline in San Antonio is 90-120 days. Fees range from $4,000-$6,500.

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