Rolling Texas Hill Country limestone hills with live oak motts, Ashe juniper, and a clear creek over white limestone cobble.
Bexar County 2024 IRC as adopted here

Barndominium Builders in San Antonio, TX

San Antonio is its own permitting authority and a well-documented one, but the honest answer about where a barndominium goes here is at the edge. The city runs the 2024 International Residential Code as Chapter 10 of the City Code, fills in Table R301.2 with its own figures, and deletes the model code's mandatory residential sprinkler outright. Only four zoning districts are sized for this building type: FR Farm and Ranch at a 25-acre minimum, RP Resource Protection at 10 acres, RE Residential Estate at one acre, and R-20 at 20,000 square feet. The city's own code says RP belongs where there is no central water and sewer. Nobody is putting a shop-house on an infill lot inside Loop 410, so we build inside the city where the site genuinely supports it, and we say plainly when the real answer is unincorporated Bexar County, Comal, Guadalupe or Bandera instead.

San Antonio at a glance

County
Bexar County
Population
1,548,422
Where we build
San Antonio, Bexar County, New Braunfels, Comal County, Guadalupe County

ZIPs 78201, 78202, 78203, 78204, 78207, 78208, 78209, 78210 and more

Site visits
We meet you on the parcel, anywhere in San Antonio or Bexar County
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Building conditions in San Antonio

What actually changes from one Texas jurisdiction to the next: who issues the permit, whether the residential code is enforced there at all, what the structure has to be engineered to, and what the ground is like. These are the numbers your drawings have to satisfy.

Build conditions for San Antonio , Bexar County, Texas : design wind speed 108 mph. BUILD CONDITIONS SAN ANTONIO, TXBexar County2024 IRCDESIGN WIND SPEED108 mphUltimate design wind speed, three-second gust, from the Table R301.2 that Section 10-37substitutes for the model table. San Antonio records no topographic effects. This is lower than…ZONING · FR FARM AND RANCH, RP RESOURCE PROTE…25 acres in FR; 10 acres in RP; 43,5…From Table 310-1 of the Unified Development Code. Maximum height inall four is 35 feet or two and a half storeys, which a barn-form…PERMIT REVIEW CLOCK3 business daysPublished review target of the issuing authorityIMPACT AND PERMIT FEESSAWS water and wastewater impact fee…The city does not set a single figure. Section 35-508(d) of theUnified Development Code, adopted under Chapter 395 of the Local…WHO ISSUES THE PERMITCity of San Antonio Development Serv…Cliff Morton Development and Business Services Center (the OneStop), 1901 S. Alamo St., San Antonio, TX 78204. Phone 210-207-1111…
Build conditions for San Antonio, drawn from the sourced facts on this page. Every figure above is cited in the quick-facts panel below, with its source and vintage.
Adopted residential code: 2024 IRC
San Antonio adopts the 2024 International Residential Code, as amended by the city, at Section 10-36 of the City Code, by Ordinance No. 2025-01-30-0075 of 30 January 2025. The energy code is a different edition again: Section 10-91 adopts the 2021 International Energy Conservation Code. There is no statewide answer in Texas, so the San Antonio edition is the one that governs and it differs from Dallas's and Fort Worth's.

City of San Antonio Code of Ordinances, Chapter 10 'Building-Related Codes of the City of San Antonio', Sections 10-36, 10-37 and 10-91 (Ord. No. 2025-01-30-0075, Sec. 1(Att. 1), 30 Jan 2025)

Design wind speed: 108 mph
Section 10-37 replaces the model Table R301.2 outright and fills it in: 108 mph ultimate design wind speed as a three-second gust, no topographic effects, seismic design category A. That figure is the city's own, and it is lower than the 115 mph Dallas publishes for the same building type.

Table R301.2 'Climatic and Geographic Design Criteria' as amended by City Code Section 10-37, adopting the 2024 IRC

San Antonio deleted the mandatory house sprinkler
The 2024 IRC requires an automatic sprinkler system in every new one- and two-family dwelling. San Antonio strikes that sentence. Section 10-37 deletes R309.2 and R309.2.1 and replaces them with a rule that only governs how a system is designed and installed where somebody chooses to install one. Texas law lets a city amend an adopted code by deleting from it, and this is that power used on one of the most consequential line items in a house built away from a municipal hydrant.

City of San Antonio Code, Section 10-37, amendment to IRC Sections R309.2 and R309.2.1 (deletions shown as bracketed strikethroughs in the adopted text); Texas Local Government Code Section 214.212(c)(1)

Four districts carry the acreage: 25, 10 and 1
Only four San Antonio zoning districts are sized for a shop-house on land. FR Farm and Ranch single-family has a 25-acre minimum lot size, RP Resource Protection 10 acres, RE Residential Estate 43,560 square feet, and R-20 20,000 square feet. All four cap height at 35 feet or two and a half storeys, which a barn-form roof clears comfortably. Every other residential district in the city is a suburban lot.

San Antonio Unified Development Code, Article III Division 2, Section 35-310.01 Table 310-1 'Lot and Building Dimensions Table' (codified through Ord. No. 2026-04-16-0257, adopted 16 April 2026)

The Edwards recharge zone reaches into the city
San Antonio maps the Edwards Aquifer recharge zone as its own overlay zoning district. Section 35-521 of the Unified Development Code establishes the Edwards Recharge Zone Overlay District over every base district, and requires a water pollution abatement plan approved by TCEQ for regulated development before a building permit or certificate of occupancy issues. TCEQ's own rules reach a private residence directly: construction at a private residence on the recharge or contributing zones falls under 30 TAC Chapter 213.

San Antonio Unified Development Code Section 35-521 'Edwards Aquifer Recharge Protection', subsections (b), (d)(1) and (g); TCEQ Edwards Aquifer Protection Program, 'Edwards Aquifer: Private Residences'

Impervious cover is the test, and roofs count
TCEQ's guidance page for private residences says an individual plan may not be required for a single-family residence if the lot is larger than five acres with no more than one residence on it, or if the residence and its associated structures do not exceed 20 percent impervious cover. The regulation is narrower than that summary. On the recharge zone the exemption at 30 TAC 213.5(h)(2) has one door only, an individual landowner building their own single-family residence who does not exceed 20 percent impervious cover, and it carries no acreage limb; the five acres that appears in the rules is 30 TAC 213.21(b), a contributing-zone provision reaching only regulated activities that disturb at least five acres or form part of a larger common plan of development. TCEQ spells out what counts: rooftops, driveways, concrete pads, sheds, sidewalks, or any impermeable surface that prevents infiltration of water into soil. A shop bay is a large roof with a concrete apron and a wide drive to reach it, so this building type meets the 20 percent line sooner than a house of the same living area does. Acreage still helps, because 20 percent of five acres is more than 43,000 square feet, but it helps through the impervious cover arithmetic rather than through a separate exemption.

TCEQ Edwards Aquifer Protection Program, 'Edwards Aquifer: Private Residences' — 'When is a Plan NOT Required?' and 'When IS a Plan Required?'; 30 TAC Chapter 213; 30 TAC 213.5(h)(2); 30 TAC 213.21(b)

Also worth knowing before you build in San Antonio

Published permit fees, banded by square footage
San Antonio publishes its whole new-residential schedule in the City Code rather than in a separate document. A 2,001 to 2,250 square foot house carries an $850 building permit and a $200 plan review, $1,450 in total basic permit fees. Plan review steps to $400 at 3,001 square feet and to $600 at 6,001. Total basic permit fees run $1,762 in the 3,001 to 3,500 band, $1,936 at 4,001 to 5,000 and $2,542 at 6,001 to 6,500. For a barndominium the step at 3,000 square feet matters, because the shop bay is what carries the building over it.

City of San Antonio Code, Section 10-39 'New residential construction fee schedule' (Ord. No. 2025-01-30-0075, Sec. 1(Att. 1), 30 Jan 2025)

5,000 square feet triggers a design professional
Section 10-8(a) of the City Code requires construction documents to be prepared by a registered design professional for any building or structure of 5,000 square feet or more in area, and for anything three storeys or higher. A barndominium is the building type that crosses 5,000 square feet without feeling large, because the shop bay counts in the building's area. Two 2,600 square foot halves under one roof trip it. The same subsection lists a geotechnical report among the submittal documents the department can require.

City of San Antonio Code, Section 10-8(a) 'Submittal documents', limbs (4) and (5)

Plan review: three business days
The city publishes a figure rather than leaving it open. New homes, room additions over 1,000 square feet, and any two-storey addition regardless of size go to the Plans Examiners, and Development Services says that review typically takes three business days. General repair and small remodel permits are issued over the counter at the One Stop.

City of San Antonio Development Services, 'Residential Permits' page, sa.gov, September 2026

A certificate of occupancy is required here
San Antonio requires a certificate of occupancy before a building is used or occupied, with an exception only for work that is exempt from permits altogether. Dallas takes the opposite approach and exempts single-family uses and the Group U structures accessory to them from the requirement entirely. Two Texas cities, two different answers, each written into its own code. San Antonio's certificate also has to state the edition of the IRC or IBC the permit was issued under.

City of San Antonio Code, Sections 10-12(a) and 10-12(b)(7); Dallas City Code Chapter 52 Section 306.1 for the contrast

The design figures are nothing like North Texas
San Antonio publishes frost line depth 0, weathering 'negligible', ground snow load 6, winter design temperature 30 degrees and mean annual temperature 68.7 degrees. Termite probability is 'moderate to heavy'. Dallas, on the same kind of table, publishes a 6-inch frost line and 'moderate' weathering. The flood cell reads 'Appendix F, UDC', because Section 10-37 repeals the IRC's flood-resistant construction section and replaces it with the city's own floodplain ordinance in the Unified Development Code.

Table R301.2 as amended by City Code Section 10-37; Section 10-37 amendment repealing IRC Section R306; Unified Development Code Section 35-522

A shop over 300 square feet is permitted work
Section 10-6(e)(1) exempts a one-storey detached accessory structure used as a tool or storage shed from permitting only where its floor area does not exceed 300 square feet. Any real workshop is over that line, so inside the city a shop is permitted, plan-reviewed and inspected like the house. There is no agricultural-building shortcut within the city limits, which is one of the sharper differences between the city and the unincorporated county around it.

City of San Antonio Code, Section 10-6(e)(1)a 'Work exempt from permit'

The city registers builders, and says so plainly
Section 10-115 requires residential construction in San Antonio to be carried out under a contractor registered with the building official, holding a home builder registration card. There are exceptions: trade subcontractors working under the registered residential building contractor do not register separately, and an owner who will hold a detached single-family dwelling for twelve months after final inspection is exempt, expressly including the accessory building. Texas has no state licence for a residential contractor, so a city registration is a permitting prerequisite, not a substitute for one.

City of San Antonio Code, Sections 10-115 and 10-116; Texas Occupations Code — no residential contractor licence exists

Nearly 500 square miles, and still growing
San Antonio covers 498.979 square miles of land, more than Dallas at 339.685 or Fort Worth at 352.011, and reached 1,548,422 residents in 2025, up 8.0 percent from a 2020 base of 1,433,348. It is not a city that ran out of room, and its zoning code carries a 25-acre district to prove it. But the land that is actually being subdivided is over the county line: Bexar County grew 7.5 percent from 2020 to 2025 while Comal grew 29.6 percent, Kendall 20.3 percent and Guadalupe 16.4 percent.

U.S. Census Bureau, 2025 Gazetteer place file for Texas (GEOID 4865000); Vintage 2025 sub-county population estimates (sub-est2025); Vintage 2025 county population estimates (co-est2025-alldata), 2020 estimates base to 1 July 2025

Outside the line, the code stops but the plat does not
Texas courts have held that a municipality cannot enforce its building code beyond its corporate limits. The Texas Supreme Court decided it for general-law cities in Town of Lakewood Village v. Bizios in 2016, and the Dallas Court of Appeals decided it for home-rule cities in Collin County v. City of McKinney in 2018, which also held the city could still require a landowner to plat. Local Government Code Section 212.049 says the same thing in statute. What does follow you out is platting: a tract escapes it above five acres in a city's extraterritorial jurisdiction, but needs more than ten acres to escape it in the county.

Town of Lakewood Village v. Bizios, 493 S.W.3d 527 (Tex. 2016); Collin County, Texas v. City of McKinney, No. 05-17-00546-CV (Tex. App.—Dallas, 10 May 2018); Texas Local Government Code Sections 212.049, 212.004(a) and 232.0015(f)

The septic permit is the county's, not the city's
On a San Antonio site with no SAWS sewer, the on-site sewage facility permit does not come from the city. TCEQ's register of authorized agents lists the Bexar County Authorized Agent as covering the entire county except the cities of Elmendorf, Hill Country Village and Shavano Park and the Town of Hollywood Park. San Antonio is not among the exceptions, so a septic system inside San Antonio city limits is permitted and inspected by Bexar County while the building itself is permitted and inspected by the city. Two authorities, one site, and the sequencing matters because the drainfield decides where the shop can go.

TCEQ On-site Sewage Facility Authorized Agent Register (OARS county search), Bexar County result, September 2026; Texas Health and Safety Code Section 366.051

Permitting authority
Development Services Department, at the Cliff Morton Development and Business Services Center, 1901 S. Alamo St., San Antonio, TX 78204. Phone 210-207-1111, Monday to Friday 7:45am to 4:30pm. Appeals from the building official go to the Building-Related and Fire Codes Appeals and Advisory Board, filed within 21 calendar days of the notice, and the board meets within 14 calendar days of receiving one.

City of San Antonio Development Services department pages, sa.gov, September 2026; City Code Sections 10-1, 10-4 and 10-14

An excavator grading a compacted building pad on a cleared lot, with survey stakes and a drainage swale visible.
Below the slab

The expensive surprises are in the ground, not the building

What moves a Texas budget is usually below grade, and it is soil rather than rock: shrink-swell clay. The Blackland Prairie and the Gulf Coast clays move enough between a wet season and a dry one to drive the foundation design across the state's largest markets, which is why several DFW cities require an engineer's seal on the foundation of every new house. Those are the same conditions that decide whether a septic field passes its soil and site evaluation, so the grading plan, the foundation and the drainfield get resolved together rather than one at a time. We price the dirt before we price the building.

What we build in San Antonio

All nine of our services — kits, custom plans, post-frame and steel construction, site preparation, permitting and engineering, through to turnkey builds — are available across Bexar County. What a project costs depends far more on the parcel than on square footage, so we work from your land rather than from a rate card.

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What a build looks like

Three stages every San Antonio project passes through, from a raw parcel to a finished home. Site work first, because that is where the budget is decided.

Aerial view of an undeveloped rural lot with cleared grass, a live oak and cedar elm treeline, and a pale gravel access track.
Stage one

The parcel

Zoning, setbacks, flood zone and utility access get checked before anything is drawn.

An excavator grading a compacted building pad on a cleared lot, with survey stakes and a drainage swale visible.
Stage two

Pad and permit

Clearing, grading and a compacted pad, while the submittal works through Bexar County.

A finished barndominium at dusk with warm interior lighting glowing through its large windows.
Stage three

Frame to finish

Shell erected and dried in, then systems, insulation and interior finish through to CO.

Those are the rules for Bexar County. Tell us what you want to build and we will draw it to them.

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Where we build around San Antonio

Bexar County and the rural land around it. The buildable acreage for a project this size usually sits outside the city limits, which is frequently what changes who issues your permit.

Our San Antonio service area, covering Bexar County and the surrounding rural acreage. This map marks the territory we serve, not a branch location.

Keep reading

The questions that usually come next once you know what San Antonio allows.

Barndominium Cost Guide

Sourced per-square-foot ranges by tier and by size, with a calculator built on the same figures.

Read it

Is It Legal in Texas?

Classification, zoning, the HOA gate, and why "nonresidential farm building" does not cover a home.

Read it

How Long Does It Take?

Census build-duration data, and what actually sets the permit clock where you are building.

Read it

Nearby areas we build in

Others we cover in this part of Texas. The permitting authority, the adopted design criteria and the zoning can all differ from one to the next.

Bexar County

Bexar County
New Braunfels

Comal County
Comal County

Comal County
Guadalupe County

Guadalupe County

Building in San Antonio: common questions

8 questions we get asked most often about building in San Antonio. If yours is not on the list, ask it directly.

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Which building code applies to a barndominium inside San Antonio city limits?
The 2024 International Residential Code, adopted with San Antonio's amendments at Section 10-36 of the City Code by Ordinance No. 2025-01-30-0075 on 30 January 2025. There is no statewide answer in Texas: every city adopts its own edition and may amend it, so the San Antonio edition is the one that governs and it is not the same as Dallas's 2021 IRC. San Antonio also splits editions between codes. The structural rules come from the 2024 IRC in Chapter 10, and the insulation spec comes from the 2021 International Energy Conservation Code adopted separately at Section 10-91. Bexar County is climate zone 2A on both the older and the 2021 maps, so the split does not change the envelope, but it is worth naming because the two chapters are not the same vintage.
Where inside San Antonio can you actually put a building like this?
Honestly, at the edge. Only four of the city's zoning districts are sized for a shop-house on land: FR Farm and Ranch single-family at a 25-acre minimum, RP Resource Protection at 10 acres, RE Residential Estate at one acre, and R-20 at 20,000 square feet. Everything else is a suburban lot, and nobody is building a barndominium on an infill lot inside Loop 410. The city says as much in its own code: Section 35-310.02 states that the RP district should not be designated in areas with central water and sewer. The good news is the height cap. All four districts allow 35 feet or two and a half storeys, so a steep barn roof is not a problem the way it can be in cities that cap at 24 feet. If you already own acreage on the city's north, west or south fringe, San Antonio is a straightforward place to permit. If you are still looking for land, the realistic search runs into unincorporated Bexar County, or north into Comal, east into Guadalupe, or west into Bandera.
What changes if the site sits over the Edwards Aquifer recharge zone?
Quite a lot, and it applies whether or not a building code does. San Antonio maps the recharge zone as an overlay zoning district over every base district. Under Section 35-521 of the Unified Development Code, a property in the overlay carries both its regular district and the overlay, the use has to be allowed in both, and a water pollution abatement plan approved by TCEQ is required for regulated development before a building permit or certificate of occupancy issues. TCEQ's own rules reach a private residence directly. Construction at a private residence on the recharge or contributing zones falls under 30 TAC Chapter 213. TCEQ's guidance page for private residences lists the ways an individual plan may not be required: a lot larger than five acres with only one residence on it, a residence and associated structures at or under 20 percent impervious cover, or a rainwater harvesting system that brings the adjusted figure down to that. The rule itself is shaped differently. On the recharge zone the exemption at 30 TAC 213.5(h)(2) turns on 20 percent impervious cover alone and has no acreage limb; the five acres in the regulation is 30 TAC 213.21(b), which brings a contributing-zone site in only where the activity disturbs at least five acres or forms part of a larger common plan of development. TCEQ counts rooftops, driveways, concrete pads and sheds as impervious cover, which is exactly what a shop bay adds. TCEQ's San Antonio regional office covering Bexar is on 210-490-3096. The parcel is the answer here, so this is settled from the map before design starts, not after.
Does San Antonio make you sprinkler a new house?
No. The 2024 International Residential Code that San Antonio adopts requires an automatic sprinkler system in every new one- and two-family dwelling, and Section 10-37 deletes that requirement. What the city keeps is the design standard: where a residential sprinkler system is installed, it has to be designed and installed in accordance with IRC Section P2904 or NFPA 13D. Texas law expressly allows a city to amend a code it adopts, including by deleting requirements from it, and this is a clear example. It matters most on a rural-edge site, where the water supply a sprinkler system would need is not something the street provides.
Do I need an engineer or a design professional for the plans?
Very likely, and the trigger is specific. Section 10-8(a) of the City Code requires construction documents to be prepared by a registered design professional for any building or structure of 5,000 square feet or more in area, and for any building three storeys or more high. A barndominium crosses 5,000 square feet without feeling large, because the shop bay counts in the building's area — two 2,600 square foot halves under one roof are already over. Separately, San Antonio did not amend IRC Section R403.1.8, so where the soil on a particular site is expansive the model code sends the foundation to engineered design under the IBC, and Texas law removes the private-dwelling exemption from engineering for a slab on expansive soil. The city can also require a geotechnical report as part of the submittal. The practical route is a Texas-licensed engineer working from a soils report for the actual parcel, and that is a question the site answers rather than a rule of thumb.
What does San Antonio charge, and how long does review take?
The city publishes both. Section 10-39 of the City Code sets the new-residential fee schedule in square-footage bands: a 2,001 to 2,250 square foot house carries an $850 building permit and a $200 plan review, $1,450 in total basic permit fees, which bundles building, electrical, mechanical, general plumbing, sewer and plan review. Plan review steps to $400 at 3,001 square feet and to $600 at 6,001, so total basic permit fees are $1,762 in the 3,001 to 3,500 band and $2,542 at 6,001 to 6,500. On timing, Development Services says a new home goes to the Plans Examiners and that review typically takes three business days. Separately from the permit, water and wastewater impact fees are the San Antonio Water System's, not the city's, and they vary by elevation zone and drainage basin — the water supply component alone was $2,592 per equivalent dwelling unit on the schedule effective 1 July 2024, and wastewater collection ranges from $768 to $4,436 depending on which basin the lot drains to. SAWS Mains and Services can price a specific address on 210-233-2009.
If my land is just outside the city, do San Antonio's rules still apply?
The building code does not follow you out; platting does. Texas courts have held that a municipality cannot enforce its building code beyond its corporate limits — the Texas Supreme Court for general-law cities in Town of Lakewood Village v. Bizios in 2016, and the Dallas Court of Appeals for home-rule cities in Collin County v. City of McKinney in 2018 — and Local Government Code Section 212.049 says the same in statute. San Antonio's own Development Services page matches that: it says the department is responsible for issuing residential building permits for property located within the city limits. What the McKinney case did uphold is the city's power to make a landowner plat in its extraterritorial jurisdiction, and a city over 100,000 carries a five-mile ring. The acreage thresholds are worth knowing because they differ: a tract escapes platting above five acres in the extraterritorial jurisdiction, but needs more than ten acres to escape it in the county. Ask the city where the line runs for your address, and read the title commitment for deed restrictions, which in rural Texas do the work zoning does elsewhere.
Does the shop need its own permit in San Antonio?
Yes, once it is any real size. Section 10-6(e)(1) exempts a one-storey detached accessory structure used as a tool or storage shed only where the floor area does not exceed 300 square feet. A workshop, an equipment bay or an attached shop is well past that, so it is permitted, plan-reviewed and inspected like the house, and it counts toward the 5,000 square foot threshold that pulls in a registered design professional. San Antonio also requires a certificate of occupancy before a building is used or occupied, with an exception only for work that needed no permit in the first place. That is a genuine difference from Dallas, which exempts single-family uses and the accessory structures serving them from the certificate requirement outright. It is a good illustration of why the answer has to be sourced city by city in Texas.

Building in San Antonio?

Start with the plan. Tell us what you want to build and we will draw it, then confirm what Bexar County will actually let you put on the parcel and what wind load it has to meet. That conversation costs nothing.

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