Building a barndominium or barn in Bandera County: permitting and site work

Bandera County does not enforce a general building code in the unincorporated county. The binding items are the septic (OSSF) permit and the county subdivision and land-development regulations, administered through the County Engineer. The City of Bandera handles permits inside the city. For a barn or barndominium out on county land, plan around the septic permit and any subdivision or access requirements rather than a building inspection.

The on-site sewage facility permit, the septic permit, is usually the binding approval for a rural Hill Country build. In Bandera County it runs through the Bandera County OSSF program, through the County Engineer. County Engineer office, 1212 Hackberry Street, second floor, Bandera: (830) 796-3175, metro (830) 460-8183, [email protected] (county Engineer page, read October 20, 2026). Confirm the current forms there before you file.

Local detail: Bandera County adopted an OSSF Order that makes the county a TCEQ Authorized Agent, adopts the state rules in 30 TAC Chapter 285 by reference and adds stricter county rules, among them a license for every system regardless of acreage. A county OSSF inspector or designated representative reviews and inspects systems. Because so much Bandera land is thin soil over limestone, an aerobic treatment unit is the common outcome rather than a conventional septic field.

Visit the official Bandera County page to confirm current forms, fees, and contacts.

The statewide 10-acre exemption does not apply in Bandera County. The county's Order Adopting Rules for On-Site Sewage Facilities (passed and approved June 14, 2007) lists its own stricter rules in Section 10, and the first, Section 10(a), says: "All on-site sewage facilities in Bandera County, Texas are required to be licensed by the Licensing Authority regardless of lot size or acreage." So a new home on a large tract still goes through the county. Thin soil over limestone usually means an aerobic treatment unit. Read at the county's own order, October 16, 2026; confirm the current requirements with the County Engineer before you design.

Bandera County is not in TCEQ's regulated Edwards Aquifer Protection Program, and despite what you may read, it is not in the regulated contributing zone either. The county sits over the Trinity and Edwards-Trinity Plateau aquifer system, hydrologically upgradient of the Edwards. In plain terms: a building project in Bandera County does not require an Edwards Water Pollution Abatement Plan. Groundwater still matters for septic and wells, but the formal Edwards recharge review does not apply here.

The Hill Country sits in the roughly 105 to 115 mph design wind speed band (3-second gust, Risk Category II) under ASCE 7-16, the standard most Texas building codes reference. Most parcels fall between mapped contours, so a designer pulls the exact value for your address from the ASCE Hazard Tool. The local twist is the topographic factor, Kzt: an exposed ridge, hilltop, or escarpment raises the effective wind pressure on a building, sometimes by half again versus flat open ground. A metal or post-frame building on a Hill Country ridge should be engineered for that, which is one reason a sealed design from the builder matters here.

Groundwater in Bandera County is managed by the Bandera County River Authority and Groundwater District, drawing largely on the Trinity aquifer. Medina Lake sits in the southeast of the county. If your build needs a well, confirm registration with the district and budget for the drill.

A 1-d-1 open-space valuation from the Bandera Central Appraisal District lowers the tax valuation on qualifying land, not on your buildings. A horse barn, arena, or barndominium is appraised separately at market value. There is no county square-footage rule that makes a building permit-free, and ag valuation does not remove the septic permit. For a structure tied to a qualifying ag use, ask the appraisal district how it is treated.

The Bandera County Subdivision and Land Development Regulations (the version posted as of January 11, 2024) treat splitting a tract into two or more lots for sale or building as a subdivision. Article Eight then sets a floor on every new lot by how it gets water and sewage. A lot with its own well and its own septic system needs at least ten acres and 200 feet on the road. A lot on a public water system with its own septic needs five acres and 150 feet. A lot on both public water and public sewer can be as small as half an acre with 100 feet of frontage, and a lot on a cul-de-sac turnaround needs a 50-foot chord.

Two details catch buyers. The acreage has to be met outside any floodway that crosses the lot, so a ten-acre tract with a creek through it can fall short. And Section 8.1.5 lets the Commissioners' Court approve a lot below the minimum only for commercial use, recorded as a covenant on the land: nobody may live, sleep or stay a single night on it, in a building, a trailer, a modular home or a tent.

State law limits when the county can make you plat at all. Under Local Government Code Section 232.0015, a county cannot require a plat outside city limits when every new lot is more than ten acres and no road or other shared ground is laid out, when the land stays in farm, ranch, wildlife or timber use, or when four or fewer lots go to relatives within the third degree. When a plat is needed, the county's fee sheet (revised February 2024) lists $3,000 plus $250 a lot for a major plat, $500 for a minor plat, and $150 plus $190 for public notice on a replat. Where the new lots will draw on groundwater, Article Four wants a Texas licensed professional engineer or geoscientist to certify that enough water is under the land.

Section 7.2.2 of the same regulations reserves a perpetual easement ten feet wide inside the front, rear and side lines of every subdivision lot for power and phone poles, wires and guy anchors, with the right to trim trees and to cross the lot to reach them. Set the slab, the shop and the porch posts outside that strip. Section 7.1.1 wants water, gas, phone and power lines buried with at least 24 inches of cover, and deeper where they cross under a road ditch.

New subdivision roads carry their own standards: a 60-foot right-of-way for local and collector roads and 100 feet for arterials, a turnaround with a 150-foot outside diameter at a permanent dead end, an eight-inch compacted base, and a paved surface of two-course surface treatment or hot mix asphalt. An entrance from a county road or state highway needs approval from the Commissioners' Court or TxDOT before the final plat. Section 6.4 adds that the county takes no responsibility for any dam that holds water or for a road built over or beside one, so a stock tank on a shared road stays the owners' to keep.

The county development permit will not move without a 911 address, and the Rural Addressing office issues one at no charge. Pick where the driveway meets the road, take the GPS coordinates at that point, and file the online request with the Property ID from the Bandera Central Appraisal District (830-796-3039) and the legal description. The county says the address arrives by email in about seven to ten business days. Post it at the house, driveway or gate in reflective numbers three inches tall or larger; Road and Bridge sells a one-sided sign for $22 and a two-sided one for $25. The office is at 3360 State Highway 173 North, 830-796-8343.

The same county fee sheet prices the septic license by system: $210 for a non-aerobic residential system under 500 gallons a day, $400 for an aerobic system or one over 500 gallons a day, $400 for a commercial system, $210 to modify a system and $45 for a re-inspection. Most limestone lots here end up in the $400 row. The flood and development permit steps are on the Bandera town page.

Clearing a building site often means a brush pile. The Bandera County Fire Marshal asks landowners to fill out the county burn registration form, or call the Sheriff's Office at 830-796-4507, before any burn.

Bandera County does not post a permit count online. Asked under the Texas Public Information Act, its Permits and Inspections office answered by email on October 28, 2026 with the number of county development permits issued: 55 from October 1 to December 31, 2023, 257 in 2024, 272 in 2025 and 203 from January 1 to October 16, 2026. That is 787 permits in a little over three years, with 2025 slightly ahead of 2024. The office did not say whether septic licenses sit inside these numbers or are counted on their own, so read them as development permits, not as new homes. Septic permit counts for Gillespie and Comal counties are in the Hill Country septic guide.