San Antonio, TX Zoning
Districts & Requirements
Every zoning district in San Antonio with permitted uses, setbacks, height limits, and density requirements — in plain English. San Antonio uses a Unified Development Code (UDC, Chapter 35) adopted in 2006 and regularly amended. The district number in residential zones indicates minimum lot size in thousands (R-6 = 6,000 SF lot). Texas SB 840, effective September 1, 2025, allows by-right multifamily and mixed-use (65%+ residential) in any commercial, office, or warehouse zone — with no FAR limits, no density caps, minimum 45-ft height, and parking capped at 1 space per unit. This fundamentally changes the math on every C-1, C-2, C-3, and O-1/O-2 parcel in the city.
19
Zoning districts
6
Overlay districts
1,530,000
Population
2025
Code adopted
Quick Reference
Find your district, see what you can do. Click any row for details.
| District | At a glance | Height | Coverage |
|---|---|---|---|
| R-6 | San Antonio's workhorse single-family district. 6,000 SF lots, 50-ft wide. One house per lot. | 2 stories / 35 ft | 45% |
| R-5 | Smaller single-family lots. 5,000 SF minimum, 45-ft wide. Common in older urban neighborhoods. | 2 stories / 35 ft | 45% |
| R-4 | Smallest SF lots in San Antonio. 4,000 SF, 35-ft wide. Urban infill and starter homes. | 2 stories / 35 ft | 45% |
| RM-4 | Fourplexes by right on 4,000 SF lots. The missing middle gateway in San Antonio. | 3 stories / 35 ft | 45% |
| MF-33 | 33 units/acre. Mid-rise apartments near commercial corridors. The sweet spot for garden-style. | 3 stories / 45 ft | 55% |
| MF-40 | 40 units/acre. Higher density apartments. 10% density bonus available with structured parking. | 4 stories / 45 ft | 60% |
| MF-50 | 50 units/acre. Urban density near downtown or major employment centers. Mid-rise product. | 5 stories / 60 ft | 65% |
| MF-65 | 65 units/acre. San Antonio's highest-density MF district. High-rise product near downtown. | No fixed max (above 5 stories with bonus) | 70% |
| O-1 | Low-rise office, 10,000 SF max building. Buffer between residential and commercial. SB 840 unlocks multifamily. | 2 stories / 35 ft (45 ft under SB 840) | 50% |
| O-2 | Mid-to-high-rise office, no building size cap. 60-ft height. SB 840 makes this a major multifamily play. | 60 ft (higher of code or 45 ft under SB 840) | 60% |
| NC | Tiny neighborhood retail. 3,000 SF building cap. Post-SB 840, multifamily now by-right. | 2 stories / 25 ft (45 ft under SB 840) | 50% |
| C-1 | Neighborhood commercial, 5,000 SF building cap. Buffer between residential and heavier commercial. | 2 stories / 25 ft (45 ft under SB 840) | 55% |
| C-2 | General commercial, no front setback max. Higher-intensity retail and service. SB 840 multifamily by-right. | 25 ft base (45 ft under SB 840) | 65% |
| C-3 | Highest-intensity commercial. No building size limit. Regional shopping centers and power centers. | 35 ft (45 ft under SB 840) | 75% |
| D | Downtown mixed-use. Any commercial or residential use. HDRC review required. Most flexible zoning. | No fixed max (HDRC review) | 100% |
| MXD | Any use permitted with site plan. No use restrictions. Urban design standards apply. | Per approved site plan | Per approved site plan |
| IDZ | Flexible infill standards. 3 intensity levels. Reduced setbacks. Matches existing block character. | IDZ-1: 35 ft / IDZ-2: 45 ft / IDZ-3: 60 ft | Per approved site plan |
| I-1 | Light-to-general industrial. Manufacturing, warehousing, flex. SB 840 multifamily by-right. | 3 stories / 45 ft | 70% |
| I-2 | Heaviest zoning. Hazardous uses, heavy manufacturing. Large buffers. SB 840 still applies. | No fixed max | 75% |
Residential — Single-Family
3 districts in San Antonio
R-6
Residential Single-FamilyThe most common single-family district in San Antonio. 6,000 SF minimum lots on 50-ft widths — standard suburban product. No multifamily, no commercial.
What you can build
- ✓Single-family detached home
- ✓Accessory dwelling unit (ADU)
- ✓Home occupation
- ✗Duplexes or multifamily
- ✗Commercial or retail
- ✗Townhouses or zero-lot-line
Key numbers
- Height
- 2 stories / 35 ft
- Lot min
- 6,000 SF
- Width
- 50 ft
- Coverage
- 45%
- Front
- 25 ft
- Side
- 5 ft
- Rear
- 20 ft
What this means in practice
45% coverage on 6,000 SF = 2,700 SF footprint. Two stories gets you ~5,000 SF of living space. The 25-ft front setback eats into the buildable area — on a 100-ft deep lot, you have 55 ft of depth to work with after front and rear setbacks. Bread-and-butter spec home product for San Antonio builders.
R-5
Residential Single-FamilyMid-density single-family on 5,000 SF lots. Found in older neighborhoods closer to downtown. Same uses as R-6 on tighter lots.
What you can build
- ✓Single-family detached home
- ✓Accessory dwelling unit (ADU)
- ✓Home occupation
- ✗Duplexes or multifamily
- ✗Commercial or retail
- ✗Townhouses
Key numbers
- Height
- 2 stories / 35 ft
- Lot min
- 5,000 SF
- Width
- 45 ft
- Coverage
- 45%
- Front
- 20 ft
- Side
- 5 ft
- Rear
- 5 ft
What this means in practice
45% of 5,000 SF = 2,250 SF footprint. The reduced rear setback (5 ft vs 20 ft in R-6) gives you significantly more buildable depth. On a 100-ft deep lot: 75 ft of usable depth. Good infill play in established neighborhoods — existing R-5 lots near commercial corridors may be rezoning candidates.
R-4
Residential Single-FamilyThe smallest standard single-family lots. 4,000 SF minimum on 35-ft widths. Common in older urban neighborhoods near downtown and along transit corridors.
What you can build
- ✓Single-family detached home
- ✓Accessory dwelling unit (ADU)
- ✓Home occupation
- ✗Duplexes or multifamily
- ✗Commercial or retail
- ✗Townhouses
Key numbers
- Height
- 2 stories / 35 ft
- Lot min
- 4,000 SF
- Width
- 35 ft
- Coverage
- 45%
- Front
- 20 ft
- Side
- 5 ft
- Rear
- 5 ft
What this means in practice
45% of 4,000 SF = 1,800 SF footprint. Two stories = ~3,400 SF total. These are tight builds — 35-ft wide with two 5-ft side setbacks leaves 25 ft of building width. The play is affordable housing or narrow-lot infill. If you're assembling R-4 lots for density, look at rezoning to RM-4 instead.
Residential — Mixed
1 district in San Antonio
RM-4
Residential MixedSan Antonio's key missing middle district. Allows single-family, duplex, triplex, fourplex, and townhouses on 4,000 SF lots with 15-ft minimum width. Up to 4 units per lot.
What you can build
- ✓Single-family (detached, attached, or townhouse)
- ✓Duplex, triplex, fourplex
- ✓Zero-lot-line homes
- ✓Accessory dwelling unit
- ✗Apartments (5+ units)
- ✗Commercial or retail
- ✗Office
Key numbers
- Height
- 3 stories / 35 ft
- Lot min
- 4,000 SF
- Width
- 15 ft
- Coverage
- 45%
- Front
- 20 ft
- Side
- 0 ft or 5 ft
- Rear
- 5 ft
What this means in practice
The 15-ft minimum lot width enables attached townhouse products. Four units on a 4,000 SF lot at 45% coverage = 1,800 SF footprint, 3 stories = ~5,400 SF total — that's four ~1,200 SF units stacked. Compare with R-4: same lot size, but RM-4 gets you 4x the units. Zero-lot-line on one side maximizes usable width.
Multi-Family
4 districts in San Antonio
MF-33
Multi-Family Medium DensityMedium-density multifamily for areas near transportation and commercial facilities. 33 units per acre. The most common MF district for conventional apartment projects outside downtown.
What you can build
- ✓Apartment buildings
- ✓Townhouse complexes
- ✓Condominiums
- ✓Senior housing
- ✓Group homes
- ✗Single-family detached
- ✗Commercial or retail (standalone)
- ✗Industrial
Key numbers
- Height
- 3 stories / 45 ft
- Lot min
- None specified
- Width
- None specified
- Coverage
- 55%
- Front
- 20 ft (max 90 ft with parking restrictions)
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 20 ft (40 ft adjacent to platted SF)
What this means in practice
33 units/acre on a 2-acre site = 66 units. At 55% coverage and 3 stories: ~143,000 SF gross. Garden-style with surface parking pencils here — you don't need structured parking at this density. The 40-ft rear setback adjacent to single-family is the deal-killer to watch for. Check what's behind the site before making an offer.
MF-40
Multi-Family Moderate-High DensityModerate-high density multifamily. 40 units per acre with a 10% density bonus if you build structured parking. Suited for sites near employment centers and transit.
What you can build
- ✓Apartment buildings
- ✓Townhouse complexes
- ✓Condominiums
- ✓Senior housing
- ✓Group homes
- ✗Single-family detached
- ✗Standalone commercial
- ✗Industrial
Key numbers
- Height
- 4 stories / 45 ft
- Lot min
- None specified
- Width
- None specified
- Coverage
- 60%
- Front
- 20 ft (max 90 ft with parking restrictions)
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 20 ft (40 ft adjacent to platted SF)
What this means in practice
40 units/acre on 3 acres = 120 units. With the 10% structured parking bonus: 132 units. At 60% coverage and 4 stories: ~313,000 SF gross. The structured parking bonus almost always pencils at this density — you likely need structured parking anyway to hit the unit count. Run the pro forma both ways.
MF-50
Urban Multi-FamilyHigh-density urban multifamily for centrally located sites near downtown, transit, or major employment. 50 units per acre with 10% structured parking bonus.
What you can build
- ✓Large apartment buildings
- ✓Condominiums
- ✓Senior housing
- ✓Group homes
- ✗Single-family detached
- ✗Standalone commercial
- ✗Industrial
Key numbers
- Height
- 5 stories / 60 ft
- Lot min
- None specified
- Width
- None specified
- Coverage
- 65%
- Front
- 20 ft (max 90 ft with parking restrictions)
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 20 ft (40 ft adjacent to platted SF)
What this means in practice
50 units/acre on 2 acres = 100 units (110 with structured parking bonus). At 65% coverage and 5 stories: ~283,000 SF gross — that's a significant mid-rise project. Structured parking is effectively required to hit this density. Plan for wrap or podium construction. Sites near Pearl, Southtown, or Medical Center are typical MF-50 locations.
MF-65
Urban Multi-Family High DensityThe densest multifamily zoning in San Antonio. 65 units per acre with 10% structured parking bonus. Applied to sites adjacent to downtown or major institutional/employment centers.
What you can build
- ✓High-rise apartment buildings
- ✓Condominiums
- ✓Senior housing
- ✓Group homes
- ✗Single-family detached
- ✗Standalone commercial
- ✗Industrial
Key numbers
- Height
- No fixed max (above 5 stories with bonus)
- Lot min
- None specified
- Width
- None specified
- Coverage
- 70%
- Front
- 15 ft
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 20 ft (40 ft adjacent to platted SF)
What this means in practice
65 units/acre on 1.5 acres = 97 units (107 with structured parking bonus). At 70% coverage you're building lot-line to lot-line with structured or below-grade parking. This is tower product — concrete construction, not wood-frame. Compare carefully with MXD or D district which may give you more flexibility on a downtown site.
Office
2 districts in San Antonio
O-1
Light OfficeLow-intensity office district typically used as a buffer between residential and commercial areas. Building size capped at 10,000 SF. Post-SB 840, multifamily is now by-right here.
What you can build
- ✓Office buildings (up to 10,000 SF)
- ✓Medical/dental offices
- ✓Multifamily housing (SB 840 by-right)
- ✓Mixed-use (65%+ residential, SB 840)
- ✗Retail or restaurant
- ✗Industrial
- ✗Drive-throughs
Key numbers
- Height
- 2 stories / 35 ft (45 ft under SB 840)
- Lot min
- None specified
- Width
- None specified
- Coverage
- 50%
- Front
- 25 ft
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 20 ft
What this means in practice
Pre-SB 840, O-1 parcels were sleepy office sites. Post-SB 840, every O-1 parcel in San Antonio is a potential multifamily site — 45-ft height, no FAR cap, no density cap, 1 parking space per unit. A half-acre O-1 site that was worth $15/SF for office could be worth $30+/SF for apartments. Run new comps on every O-1 parcel near transit or employment.
O-2
High-Rise OfficeHigh-intensity office district allowing low-to-high-rise buildings with no size cap. 60-ft height limit. Post-SB 840, by-right multifamily with no FAR limits makes O-2 parcels extremely valuable for residential conversion.
What you can build
- ✓Office buildings (no size limit)
- ✓Medical complexes
- ✓Multifamily housing (SB 840 by-right)
- ✓Mixed-use (65%+ residential, SB 840)
- ✗Retail or restaurant (standalone)
- ✗Industrial
- ✗Drive-throughs
Key numbers
- Height
- 60 ft (higher of code or 45 ft under SB 840)
- Lot min
- None specified
- Width
- None specified
- Coverage
- 60%
- Front
- 25 ft
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 20 ft
What this means in practice
O-2 at 60 ft and no building size limit was already strong for office. With SB 840 removing FAR and density caps, a 1-acre O-2 site at 60% coverage and 5 stories yields ~130,000 SF of residential — roughly 130 apartments. Parking capped at 1 per unit under SB 840, not the usual 1.5-2. Medical Center and UTSA corridor O-2 parcels are the immediate targets.
Commercial
4 districts in San Antonio
NC
Neighborhood CommercialSmall-scale neighborhood commercial limited to 3,000 SF buildings. Designed for corner stores and services. SB 840 now allows multifamily by-right on these parcels — dramatically changing their highest and best use.
What you can build
- ✓Small retail/service (up to 3,000 SF)
- ✓Office
- ✓Multifamily housing (SB 840 by-right)
- ✓Mixed-use (65%+ residential, SB 840)
- ✗Drive-throughs
- ✗Auto-oriented uses
- ✗Industrial
- ✗Large-format retail
Key numbers
- Height
- 2 stories / 25 ft (45 ft under SB 840)
- Lot min
- None specified
- Width
- None specified
- Coverage
- 50%
- Front
- 20 ft
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 20 ft
What this means in practice
NC parcels were historically low-value due to the 3,000 SF building cap. SB 840 blows the lid off: by-right multifamily at 45 ft, no FAR, no density cap, 1 parking space per unit. An NC corner lot at a busy intersection is now a potential 40-unit apartment site. The land value arbitrage is significant — many NC parcels haven't repriced yet.
C-1
Light CommercialLight commercial serving as a buffer between residential and more intense C-2/C-3 districts. 5,000 SF building size cap. SB 840 unlocks by-right multifamily.
What you can build
- ✓Retail and service (up to 5,000 SF)
- ✓Office
- ✓Restaurants
- ✓Multifamily housing (SB 840 by-right)
- ✓Mixed-use (65%+ residential, SB 840)
- ✗Large-format retail
- ✗Auto-oriented uses
- ✗Industrial
Key numbers
- Height
- 2 stories / 25 ft (45 ft under SB 840)
- Lot min
- None specified
- Width
- None specified
- Coverage
- 55%
- Front
- 20 ft
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 20 ft
What this means in practice
Same SB 840 story as NC but with slightly larger commercial entitlement. C-1 parcels along arterials are the lowest-hanging fruit for SB 840 multifamily plays — they're often underimproved, cheap, and surrounded by commercial uses that won't complain about apartments. Look for C-1 sites on bus routes near employment.
C-2
CommercialGeneral commercial district for retail, service, and office uses more intensive than C-1. No building size limit. SB 840 makes every C-2 parcel a potential multifamily site.
What you can build
- ✓Retail and restaurants
- ✓Office (any size)
- ✓Hotels and motels
- ✓Auto sales and service
- ✓Multifamily housing (SB 840 by-right)
- ✓Mixed-use (65%+ residential, SB 840)
- ✗Heavy industrial
- ✗Manufacturing
- ✗Salvage operations
Key numbers
- Height
- 25 ft base (45 ft under SB 840)
- Lot min
- None specified
- Width
- None specified
- Coverage
- 65%
- Front
- No maximum
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 10 ft
What this means in practice
C-2 is the biggest SB 840 play in San Antonio. Thousands of C-2 parcels along every major corridor — Fredericksburg Rd, Bandera Rd, Nacogdoches, Military Dr — can now support by-right multifamily at 45 ft, no FAR, no density cap, 1 space per unit. A 1-acre strip center site could yield 100+ apartments. The 25-ft base height is irrelevant under SB 840.
C-3
General CommercialSan Antonio's most intensive commercial district. No building size restrictions, 35-ft height. Regional malls, power centers, and large-format retail. SB 840 by-right multifamily applies here too.
What you can build
- ✓Large-format retail
- ✓Regional shopping centers
- ✓Office complexes
- ✓Hotels
- ✓Entertainment venues
- ✓Multifamily housing (SB 840 by-right)
- ✗Heavy industrial
- ✗Manufacturing
- ✗Hazardous material processing
Key numbers
- Height
- 35 ft (45 ft under SB 840)
- Lot min
- None specified
- Width
- None specified
- Coverage
- 75%
- Front
- No maximum
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 10 ft
What this means in practice
C-3 parcels are typically large — 5+ acres for power centers. Under SB 840, a dying big-box site becomes a 200-400 unit apartment complex by-right. No rezoning, no public hearing, no NIMBYs. The existing C-3 parking lots provide staging area during construction. Watch for deed restrictions that may limit residential use even where zoning allows it.
Downtown
1 district in San Antonio
D
DowntownSan Antonio's central business district zoning. Allows concentrated retail, service, office, residential, and mixed-use. HDRC (Historic and Design Review Commission) approval required for most projects.
What you can build
- ✓Mixed-use buildings
- ✓Apartments (up to 50 units/acre base)
- ✓Hotels
- ✓Office (no size limit)
- ✓Retail and restaurants
- ✓Entertainment venues
- ✗Heavy industrial
- ✗Auto-oriented (car wash, gas station)
- ✗Outdoor storage
Key numbers
- Height
- No fixed max (HDRC review)
- Lot min
- None
- Width
- None
- Coverage
- 100%
- Front
- 0 ft (build-to line)
- Side
- 0 ft
- Rear
- 0 ft
What this means in practice
D district land trades at a premium because you can build lot-line to lot-line with virtually any use. The constraint is HDRC — every exterior modification visible from a public right-of-way requires a Certificate of Appropriateness. Budget 2-4 months for HDRC review. River Walk-adjacent sites have additional RIO (River Improvement Overlay) requirements. Below-grade or structured parking is the norm.
Special District
2 districts in San Antonio
MXD
Mixed-Use DistrictSan Antonio's most flexible special district. Does not regulate land uses — any use is permitted subject to an approved zoning site plan. Must include both residential and commercial components. Urban design standards maintain pedestrian scale.
What you can build
- ✓Any residential use
- ✓Any commercial use
- ✓Office
- ✓Mixed-use (required)
- ✓Hotels
- ✓Civic uses
- ✗Projects that fail urban design review
- ✗Uses inconsistent with approved site plan
- ✗Heavy industrial
Key numbers
- Height
- Per approved site plan
- Lot min
- Per approved site plan
- Width
- Per approved site plan
- Coverage
- Per approved site plan
- Front
- Per approved site plan
- Side
- Per approved site plan
- Rear
- Per approved site plan
What this means in practice
MXD is essentially a PUD (Planned Unit Development) with urban design teeth. The standards are negotiated through the site plan process, not set by the code. This gives you maximum flexibility but adds entitlement risk — your project is whatever the city approves. Pearl Brewery, Hemisfair, and several Broadway corridor projects use MXD. Plan for a longer entitlement timeline but more creative development program.
IDZ
Infill Development ZoneDesigned for infill and reuse of underutilized parcels. Three intensity levels: IDZ-1 (limited), IDZ-2 (mid), IDZ-3 (high). Front setback matches existing median on the block face. Non-residential gets 0-ft side/front setbacks with 5-ft rear minimum.
What you can build
- ✓Single-family, duplex, triplex, quadplex
- ✓Apartments (IDZ-2, IDZ-3)
- ✓Mixed-use
- ✓Retail and office
- ✓Live/work
- ✗Heavy industrial
- ✗Uses incompatible with neighborhood context
- ✗Auto-oriented uses (IDZ-1)
Key numbers
- Height
- IDZ-1: 35 ft / IDZ-2: 45 ft / IDZ-3: 60 ft
- Lot min
- Varies by intensity level
- Width
- Varies by intensity level
- Coverage
- Per approved site plan
- Front
- Within 10% of block median
- Side
- 0 ft (non-residential) / 5 ft (residential)
- Rear
- 5 ft minimum
What this means in practice
IDZ is San Antonio's answer to form-based zoning for infill sites. The 10% median setback rule means your building matches the existing street wall — no arbitrary 25-ft setback in an urban area. IDZ-3 at 60 ft is effectively a mid-rise entitlement without going through a full MXD or D rezoning. Adopted in 2018, primarily applied along Broadway, St. Mary's, and South Flores corridors.
Industrial
2 districts in San Antonio
I-1
General IndustrialGeneral industrial accommodating manufacturing, fabrication, warehousing, and distribution. SB 840 makes multifamily by-right here — warehouse-to-residential conversions are now possible without rezoning.
What you can build
- ✓Manufacturing and fabrication
- ✓Warehousing and distribution
- ✓Auto repair and service
- ✓Flex/R&D space
- ✓Multifamily housing (SB 840 by-right)
- ✗Heavy industrial with major hazards
- ✗Salvage and junkyard operations
- ✗Residential (pre-SB 840)
Key numbers
- Height
- 3 stories / 45 ft
- Lot min
- None specified
- Width
- None specified
- Coverage
- 70%
- Front
- 25 ft
- Side
- 10 ft (15 ft adjacent to SF)
- Rear
- 10 ft
What this means in practice
I-1 land near urban areas is the sleeper SB 840 play. Warehouse and industrial parcels along IH-10 near downtown, Brooks, and the Lone Star corridor can now go multifamily by-right at 45 ft, no FAR, 1 parking space per unit. These sites are often 2-5 acres with existing infrastructure. The question is environmental — get a Phase I before tying up any I-1 site for residential conversion.
I-2
Heavy IndustrialSan Antonio's heaviest industrial district. Accommodates uses that are hazardous or generate heavy truck traffic. SB 840 technically allows by-right multifamily, but environmental conditions often make residential infeasible.
What you can build
- ✓Heavy manufacturing
- ✓Chemical processing
- ✓Salvage and recycling operations
- ✓Truck terminals
- ✓Multifamily housing (SB 840 by-right, technically)
- ✗Residential (pre-SB 840, practical limitations remain)
Key numbers
- Height
- No fixed max
- Lot min
- None specified
- Width
- None specified
- Coverage
- 75%
- Front
- 25 ft
- Side
- 15 ft
- Rear
- 15 ft
What this means in practice
I-2 parcels technically qualify for SB 840 multifamily, but don't get excited yet. Phase I and Phase II environmental assessments are mandatory for any residential conversion. Remediation costs can kill the deal. The better play for I-2 sites is long-term: hold for eventual rezoning as the area transitions, or build industrial product at current zoning. Kelly Field area, East Side, and South San are typical I-2 locations.
Development Bonus Program
San Antonio offers two density bonus paths. First, UDC Section 35-360 provides density bonuses for projects incorporating open space, transit access, and other public amenities — specific incentives are listed in Table 360-2. Second, Section 35-372 provides an affordable housing density bonus: set aside 10% of units for low-income households and get a 20% density increase, or 5% for very low-income for the same 20% bonus. In MF-40, MF-50, and MF-65 districts, an additional 10% density bonus is available when all parking is in structured garages. Post-SB 840, the state-level density deregulation in commercial zones may make these local bonuses less relevant for commercial-zone conversions — but they still matter for MF and residential rezonings.
Overlay Districts
Historic and Design Review Commission (HDRC) Districts
San Antonio has 30+ local historic districts plus the downtown core under HDRC jurisdiction. Any exterior modification visible from a public right-of-way requires a Certificate of Appropriateness. Demolition requires HDRC approval. Budget 2-4 months for review. King William, Lavaca, Dignowity Hill, Monte Vista, and Tobin Hill are the major residential historic districts developers encounter. Non-compliance results in fines and required restoration.
River Improvement Overlay (RIO)
Covers properties within 100-300 ft of the San Antonio River. Four sub-districts (RIO-1 through RIO-4) with escalating design standards. RIO-1 (downtown) is the strictest: building orientation toward the river, pedestrian connectivity, and specific materials. Adds design review and can restrict building placement. Critical for any River Walk-adjacent development — the overlay, not the base zoning, is often the binding constraint.
Edwards Aquifer Recharge Zone (ERZD)
Covers the Edwards Aquifer recharge and contributing zones on the north and northwest sides. Impervious cover limits (15-30% depending on zone), stormwater controls, and water quality requirements. This is the single biggest development constraint on San Antonio's growth frontier — it caps density on large swaths of the I-10 West and US-281 North corridors. Check the ERZD map before acquiring any site north of Loop 1604.
Airport Hazard Overlay
Covers approach and departure zones for San Antonio International, Lackland AFB, Randolph AFB, and Stinson Municipal airports. Height restrictions limit building height near runways. Critical constraint along US-281 near the airport — some sites have a 150-ft or lower height cap even if base zoning allows more.
Military Base Compatibility Overlay
Buffers around Lackland AFB, Randolph AFB, Fort Sam Houston, and Camp Bullis. Noise contour zones restrict residential density. Joint Land Use Study (JLUS) recommendations affect rezoning decisions. San Antonio's military installations are the city's largest employers — the city takes base compatibility seriously and will deny rezonings that conflict with military operations.
FEMA Flood Overlay
Significant flood risk throughout San Antonio, especially along creeks and the San Antonio River watershed. Check FEMA FIRM panels before making any offer. Base flood elevation determines first-floor height. Floodway parcels are essentially unbuildable for new construction. The 2018 FIRM update significantly expanded flood zones in some areas — verify with current maps, not old surveys.
Frequently Asked Questions
How do I check zoning for a specific San Antonio property?
Use the City's One Stop Map at gis.sanantonio.gov/DSD/OneStop — enter an address to see base zoning, overlays, flood zones, and historic districts. For what the zoning means for your development, you need to cross-reference the base district with any applicable overlays (HDRC, RIO, ERZD, airport, military). The overlay is often the binding constraint, not the base zoning.
How does Texas SB 840 change development in San Antonio?
Effective September 1, 2025, SB 840 allows by-right multifamily and mixed-use (65%+ residential) in any commercial, office, or warehouse zone. No rezoning, no public hearing. Height minimum of 45 ft, no FAR limits, no density caps, parking capped at 1 space per unit. This applies to every NC, C-1, C-2, C-3, O-1, O-2, I-1, and I-2 parcel in San Antonio. The practical impact: thousands of underperforming commercial parcels along major corridors are now viable multifamily sites.
What is the HDRC and when does it apply?
The Historic and Design Review Commission reviews any exterior work visible from a public right-of-way in local historic districts, downtown, and near the San Antonio River. Certificate of Appropriateness required before building permit. Demolition in historic districts requires separate HDRC approval. Expect 2-4 months for review. If you're buying in King William, Monte Vista, Tobin Hill, Lavaca, or downtown, HDRC review is guaranteed — factor it into your timeline and budget.
What's the Edwards Aquifer overlay and how does it limit development?
The Edwards Recharge Zone District (ERZD) caps impervious cover at 15-30% on San Antonio's north and northwest growth frontier. This means a 10-acre site in the recharge zone might only support 2-3 acres of building and parking. It's the single biggest density constraint on the city's most desirable suburban land. Check the ERZD map before acquiring any site north of Loop 1604 or west of I-10.
What's the difference between MF-33, MF-40, MF-50, and MF-65?
The number is the max units per acre. MF-33 is garden-style apartments with surface parking (3 stories, 45 ft). MF-40 adds a structured parking density bonus (4 stories). MF-50 is urban mid-rise near downtown or transit (5 stories, 60 ft). MF-65 is the highest density — tower product near downtown. Each step up requires more expensive construction but yields more units per acre. The 40-ft rear setback adjacent to single-family applies to all of them.
Can I build mixed-use in San Antonio?
Several paths. The D (Downtown) district allows mixed-use by-right. MXD (Mixed-Use District) is a site-plan-based special district for master-planned mixed-use. IDZ (Infill Development Zone) allows mixed-use in infill areas at three intensity levels. And post-SB 840, any commercial zone allows mixed-use with 65%+ residential by-right. For ground-up mixed-use outside downtown, MXD or IDZ gives you the most design flexibility, while SB 840 on a C-2 site is the fastest path.
Are there military overlay restrictions I should know about?
San Antonio has five major military installations. Noise contour overlays restrict residential density near Lackland, Randolph, and Fort Sam Houston. The Camp Bullis area on the far north side has additional light pollution and land use restrictions. The city actively enforces JLUS compatibility recommendations in rezoning decisions. If your site is within 3 miles of a military installation, check the compatibility overlay before proceeding.
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