Accessory Dwelling Units

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Cliff Morton Development and Business Services Center
1901 S. Alamo St.
San Antonio, TX 78204

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Phone:
210-207-1111

Hours:
7:45 a.m. - 4:30 p.m. (Mon - Fri)
Closed on City Holidays

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Requirements

The City of San Antonio has recently amended the Affordable Housing Initiative to provide quality affordable housing to all citizens regardless of income level. Accessory dwelling units (ADUs) have become a source of income to help families remain in their homes while providing affordable housing to elderly, single-person households, and students.

The following requirements must be met for an ADU:

Category Requirement

Owner Occupancy

  • Owner must reside at the main house or in the ADU
  • Properties where owner does not live on site must be rezoned to allow more than one dwelling unit

Permitted Zoning Districts

  • R-1, R-2, R-3, R-4, R-5, R-6, RM-4, RM-5, RM-6 and in multi-family districts up to a total of five (5) units

Size

  • Up to 800 square feet or 50% of the size of main house (whichever is larger)
  • Cannot exceed 1,600 square feet
  • All properties, regardless of main home size, can have an ADU of at least 800 square feet
  • Applies to attached and detached ADUs

Bedrooms

  • No limit on number of bedrooms

Utilities

  • Can have separate utilities (meters) or can share meter with main house

Height

  • Detached ADUs =limited to 2 stories and 25 feet in height
  • Attached ADUs = must comply with height limit restrictions for the underlying zoning district

Setbacks

  • Detached ADUs = may be located 3 feet or more from side and rear property lines
    • Cannot have an eave overhang within 3 feet of the property line
    • Must be fire rated if within 5 feet of the property line
  • To avoid above measures, setbacks from side and rear property lines must be 5 feet

Parking

  • Only ADUs over 800 square feet require a dedicated off-street parking space

Applying for a permit

HOW TO APPLY FOR A PERMIT

Permits are obtained through the BuildSA portal.

To acquire a permit, follow the steps below:

  • Fill out the affidavit acknowledging the property owner must live on site for the legal use and occupancy of the ADU. This affidavit must be recorded in Bexar County’s public records.
  • Submit permit application through BuildSA. Click on “Residential Building Permit Application.” View the Information Bulletin 402 for detailed instructions. Please include proof affidavit was recorded as part of the application packet. Proof of residency is required by voter registration, copy of driver's license, etc.
  • Once application is received, it will be placed in queue for intake under completeness review for up to 3 business days. When all the required materials are submitted, staff will verify the application is complete.
  • Plan review fee is invoiced, and once paid, the application is automatically routed to a plan reviewer. This technical review can take up to 3 business days for the initial redline comments. Once plan is approved, permit fees are applied to the application. After payment is received, the permit is issued.
  • Inspectors review construction for compliance with adopted building codes. Once all inspections pass, the Certificate of Occupancy is issued and the ADU may be occupied.

Incentives

Construction of an ADU may qualify for waiver of:

  • City development and permitting fees, and
  • SAWS water and wastewater impact fees

To qualify:

  • Either primary unit or ADU must be reserved for a household earning at or below 80% AMI, and
  • Rent may not exceed 30% of household's monthly income. This restriction must remain in place for 5 years after issuance of a Certificate of Occupancy.

For more information, email: COSAFeeWaivers@sanantonio.gov or view website.