San Antonio

1. UDC 35-371 eligibility and overlay check (~5d)
   Confirm parcel zoning permits an ADU under UDC 35-371 (allowed in single-family residential districts; FR and RE district size cap differs). Check for Edwards Aquifer Recharge Zone (ERZD overlay per UDC 35-332), Military Lighting Overlay (Camp Bullis / Lackland / Randolph), Historic Districts (HL/H), and ETJ status (parcels in Bexar ETJ follow county building rules and TCEQ Edwards Aquifer Protection Plan instead of city UDC).
2. Pre-application owner-occupancy declaration (~7d)
   UDC 35-371(c) requires the owner to occupy either the principal unit or the ADU as permanent residence; the owner-occupied unit cannot be rented. Notarized affidavit of owner-occupancy is filed with Development Services as part of intake. Properties under prior CUP (Conditional Use Permit) restrictions may need a separate zoning verification letter.
3. Submit Residential Building Permit via San Antonio BuildSA portal (~2d)
   Application submitted through BuildSA at aca.sa.gov. Required: completed Residential Building Permit application, ADU site plan showing the 800 sqft cap (1,200 sqft if RE-zoned) and connection to principal-structure water/sewer/electric (electrical can be separate beyond 100 linear feet per UDC 35-371(d)), sealed structural plans, energy compliance per IECC 2021 Climate Zone 2A, T-pole or temporary power request if needed.
4. DSD intake and routing review (~3d)
   Development Services Department (DSD) intake staff reviews for completeness, assigns concurrent reviews to Building, Zoning, Fire, MEP, and (if applicable) SAWS Aquifer Protection. DSD's published target for residential plan review is 3 to 18 business days depending on project type and current load.
5. Plan review (building, zoning, fire, MEP, SAWS) (~18d)
   Concurrent review across disciplines. Typical first-cycle comments cover setbacks (5 ft side/rear minimum in most SF districts), max height (one story over the principal not exceeded), parking (one off-street space if not within 1/2 mile of VIA frequent transit), and SAWS impact-fee calculation. ERZD parcels add a TCEQ-coordinated Edwards Aquifer Protection Plan (EAPP) review which can extend this stage by 30-60 days.
6. Permit issuance and fee payment (~5d)
   Once plans are approved, applicant pays building permit, plan-review, and SAWS water/sewer impact fees through BuildSA. Permit valid 180 days from issuance per City of San Antonio Building Code; one extension available on showing of progress.
7. Construction inspections
   Required DSD inspections: foundation/T-pole, plumbing rough, electrical rough, mechanical rough, framing, insulation, final building, final MEP, fire (if sprinklered). Inspections scheduled through BuildSA portal or at +1-210-207-1111. Common rework items: setback verification, opening protection if within Wind Zone 90 mph design contour.
8. Certificate of occupancy (~5d)
   DSD issues CO after all final inspections pass. ADU may then be occupied. Owner-occupancy affidavit remains a continuing condition; STR registration with Code Enforcement is separate (Type 1 owner-occupied STR is the only permissive STR designation for ADUs under San Antonio's STR ordinance).

• Long-term rental: yes Long-term rental of ADU generally permitted; landlord-tenant law and any city rental-registration ordinance apply.
• Short-term rental: with-restrictions STR rules vary by city. San Antonio regulates STRs separately from ADU permitting; check local STR ordinance and HOA covenants.
• Office rental: with-restrictions Detached office rental requires home occupation permit or rezoning.
• Home office: yes Home occupation permitted with restrictions on signage and customer traffic.
• Studio / workshop: yes Personal artist studio is a permitted accessory use.
• Agriculture: with-restrictions Limited urban agriculture permitted in residential zones; livestock varies by district.
• Relative support: yes Family-occupancy ADU explicitly permitted in single-family zones.

Pre-approved plans Pre-approved plans

Staff: DSD Residential Plan Review (Residential Building Permits / ADU intake), DSD Land Development / Zoning (Zoning Verification Letter and UDC 35-371 interpretations), SAWS Aquifer Protection (Edwards Aquifer Recharge Zone (ERZD) coordination for parcels in the recharge or contributing zones)

• Water: San Antonio Water Utility · 30d connect · $4,500
• Sewer: San Antonio Sewer / Wastewater · 30d connect · $5,500
• Electric: San Antonio Electric Utility · 21d connect · $1,800
• Gas: San Antonio Gas Utility · 30d connect · $1,500

Realistic total: best 7mo · typical 10mo · worst 16mo

State ADU loans:

• Texas Department of Housing and Community Affairs (TDHCA)
• Texas State Affordable Housing Corporation (TSAHC)

Texas has no HOA-ADU preemption; HOA covenants restricting ADUs are enforceable.

• historic-district
  San Antonio historic districts trigger Architectural Review Board / Historic Preservation Commission review for ADUs in historic boundaries.
• airport-noise-zone
  Airport noise contours affect some parcels and may require sound-attenuation construction.