San Antonio Setbacks & Height Limits — Residential Zones

Fact-checked against the current San Antonio Unified Development Code on September 20, 2026.

San Antonio's base lot and building dimensions are in UDC Section 35-310.01, Table 310-1. The table itself states that its dimensions govern if an illustration conflicts with the table, while Sections 35-515 through 35-517 contain additional rules for lot layout, height, and density/intensity.

Common Single-Family Residential Districts

The current Table 310-1 uses these base dimensions for several common residential districts:

The previous version of this page overstated several setbacks. It listed 20-ft front setbacks for R-4 and R-5, 25 ft for R-6 and R-20, and rear setbacks of 15–25 ft. Those figures do not match the current Table 310-1.

Do Not Add a Generic 15-ft Corner-Lot Rule

The earlier page also stated that residential corner lots “typically require” a 15-ft side-street setback. That broad statement has been removed.

San Antonio's UDC contains separate interpretation rules, special setbacks, overlay requirements, and street-related standards. A corner lot must be checked under the provisions that actually apply to the parcel rather than by adding a generic number to Table 310-1.

Height Measurement

For Table 310-1, the UDC defines height using the average elevation of the finished lot grade at the front of the building and then a roof-type-specific reference point. For example, a gable, hip, or gambrel roof is measured to the average height between the plate and ridge rather than simply to the roof's highest point.

This matters because “35 ft” should not be interpreted as a universal measurement to the topmost roof element.

Additional setbacks can also be required for height increases under Section 35-517.

Overlays and Special Areas

Base zoning is only part of the review. San Antonio has overlay and special-district standards that can affect height, setbacks, design, or review, including historic districts, River Improvement Overlay areas, airport-related controls, military-related areas, and other mapped districts.

The applicable overlay should be confirmed from the parcel's current zoning information rather than inferred from neighborhood name alone.

Accessory Structures and ADUs

Garages, sheds, accessory dwelling units, and other accessory structures have additional UDC provisions. Do not use the principal-building table above as the complete accessory-structure rule.

For accessory dwelling information, see the San Antonio ADU rules page and verify the current UDC provisions and any applicable state law before relying on a design.

Pre-Existing Lots and Other Exceptions

The UDC contains alternative dimensional provisions for certain pre-existing lots and other exceptions. A parcel that predates current subdivision standards may therefore require a different analysis from a newly created lot.

How to Check a Property

1. Confirm the parcel's current zoning district and overlays through City of San Antonio resources.
2. Read Table 310-1 for the base district dimensions.
3. Check Sections 35-515 through 35-517 for interpretation, layout, height, and density rules.
4. Check historic, river, airport, military, and other overlay provisions where mapped.
5. Check accessory-structure provisions separately if the project is not the principal building.
6. Confirm uncertain conditions with Development Services before final design or permitting.

Official Sources

• San Antonio Unified Development Code — Municode
• City of San Antonio Development Services
• Development Services Documents Online

This guide is informational only. The current UDC, mapped overlays, and parcel-specific conditions control. Verify current requirements with San Antonio Development Services before design, permitting, purchase, or construction decisions.