The Central Texas barndominium permit directory
One row for each of the six counties. The house permit column repeats the county's own official site as of the printed date, with a link to the page, and never says more than the county did. The septic, flood and driveway offices are the ones each county names itself. On a lot inside a city, that city's building department is the one that applies.
| County | The house, outside town | Septic for the house | Flood zone review | Your driveway off the county road | The office to phone | Page we read, and when |
|---|---|---|---|---|---|---|
| Llano CountyLlano | A county permit is required before you build outside city limits, and the county does not inspect the structure outside a flood hazard area. As read at the county’s own pages, September 13, 2026. | Llano County Development Services, or the Lower Colorado River Authority inside its water quality zone, call 325-247-2039. The county is the state’s authorized agent and permits every system whatever the tract size. The county’s subdivision rules point lots inside the river authority’s zone at that agency’s rules. | Llano County Development Services, for the county Floodplain Administrator, call 325-247-2039. A floodplain development permit is required for any development in a special flood hazard area. | The county commissioner for your precinct, in writing, plus a county road cut permit. Nothing may be installed on a county right of way, driveways and culverts included, without the precinct commissioner’s written permission. | Llano County Development Services, call 325-247-2039. | Llano County Development Services, as read September 13, 2026. |
| Burnet CountyBurnet | A county permit is required before you build outside city limits, and the county does not inspect the structure outside a flood hazard area. As read at the county’s own pages, September 13, 2026. | Burnet County Development Services, or the Lower Colorado River Authority inside its water quality zone, call 512-715-5260. The county permits and inspects every on-site system whatever the size of the tract, which sets aside the state acreage exception. The county publishes a link to the river authority’s jurisdiction map but does not say which lake lots sit within it. | Burnet County Development Services, for the Floodplain Administrator appointed by Commissioners Court, call 512-756-5445. One foot of freeboard above base flood elevation is required and two feet is recommended in an A zone. | The county commissioner for your precinct, on a county road access permit. The commissioner sets culvert location, length and diameter at a site meeting, and driveway approval must be in hand before a 911 address is assigned. TxDOT approves a driveway onto a Farm to Market, Ranch Road or State Highway. | Burnet County Development Services, call 512-715-5260. | Burnet County On-Site Sewage Facilities and Development Services, as read September 13, 2026. |
| Williamson CountyGeorgetown | The county states it issues no building permits for the unincorporated county. Other county permits still apply. As read at the county’s own pages, September 13, 2026. | Williamson County Engineer’s Office, the on-site sewage facility program, call 512-943-3330. The County Engineer runs the program on the state’s authority. Applications are taken online through the county portal only, after the Certificate of Compliance is processed. | Williamson County Engineer’s Office, the county Floodplain Administrator, call 512-943-3330. Building in or beside the 100-year floodplain takes a floodplain development permit. The structure has to sit a foot or more above base flood elevation, and a licensed surveyor files a FEMA elevation certificate two times: once the slab is in, and at completion. | Williamson County Road and Bridge Division, on a county driveway permit. Required for a new or modified driveway onto a county-maintained road, with the county sizing the culvert. | Williamson County Engineer, Road and Bridge Division, call 512-943-3330. | Williamson County frequently asked questions, County Engineer, as read September 13, 2026. |
| Travis CountyAustin | A county permit is required before any development outside city limits, and inspections are required during the build. As read at the county’s own pages, September 13, 2026. | Travis County TNR, the state’s authorized agent for the unincorporated county, or the Lower Colorado River Authority near Lake Travis, call 512-854-4438. The county states no lot-size exemption at all: every system in its jurisdiction is covered whatever the size of the lot, and the minimum lot size for a home on a septic system is one acre. | Travis County TNR, the county Floodplain Administrator. Full architectural and site plans, lowest floor elevations and a flood venting plan, an elevation certificate before framing starts and a finished-construction certificate within 30 days, and no effect on the base flood elevation. | Travis County TNR for a county-maintained road, TxDOT for a state road. The county issues no permit for a driveway onto an unmaintained or unaccepted road. Approaches are concrete, meet the road at about 90 degrees, and use corrugated metal culvert pipe at least 18 inches across. | Travis County TNR Development Services permit desk, call 512-854-4215. | Travis County Transportation and Natural Resources, Development Services, as read September 13, 2026. |
| Bastrop CountyBastrop | A county permit is required before any development outside city limits, and inspections are required during the build. As read at the county’s own pages, September 13, 2026. | Bastrop County Environmental and Sanitation, the state’s authorized agent, call 512-581-4042. Every septic installation or modification needs a county permit regardless of acreage, which sets aside the state acreage exception. Minimum lot size is half an acre with a public water supply and one acre without one. | Bastrop County Floodplain Administrator, inside Development Services, call 512-581-7159. Two feet of freeboard above base flood elevation, extended to some Zone X areas where base level engineering has set flood depths, with a surveyor certifying the elevation. | Bastrop County Development Services, engineering inspector, for a county-maintained road; TxDOT for a state highway, call 512-581-4039. The driveway is part of the same county development application. | Bastrop County Development Services, call 512-581-7176. | Bastrop County Development Services, as read September 13, 2026. |
| Caldwell CountyLockhart | A county permit is required before you build outside city limits, and the county does not inspect the structure outside a flood hazard area. As read at the county’s own pages, September 13, 2026. | Caldwell County Sanitation Department, the state’s authorized agent, call 512-398-1803. The county requires an application, permit and inspection whatever the size of the tract, which sets aside the state acreage exception. Minimum lot size is one acre, only a licensed installer may build the system, and the septic permit is one of the papers the construction permit needs. | Caldwell County Director of Sanitation, the county Floodplain Administrator, call 512-398-1803. A floodplain development permit is required for all construction and other development in the mapped flood zones, manufactured homes included. | Caldwell County Unit Road Department, call 512-398-7269. A driveway permit stays in force even on a tract exempt from platting. | Caldwell County Sanitation and Development Services, call 512-398-1803. | Caldwell County Development Ordinance, revised February 14, 2023, as read September 13, 2026. |
Which rules follow a house into all six counties?
Four of them. A lot with no sewer line needs a septic permit, from the county or from the river authority if the lot sits in its lake zone, and it comes after a site evaluation, with a state-licensed installer doing the work. Any part of the parcel inside a mapped flood hazard area brings floodplain review. A new entrance onto a county road needs a driveway or culvert permit. And Texas has no builder license anywhere, so the contract, the insurance certificate and the engineered plans are what hold a builder to a standard.
Office of the Texas Governor, Business Permit Office, Texas Business Licenses and Permits Guide, as read September 13, 2026.
LCRA On-Site Sewage Facilities Program, as read September 13, 2026.
Why does each county give a different answer?
Beyond city limits, Texas hands most house-building rules to the county, and each of these six made its own call. Which counties want a building permit walks through what that means for your house.
How does a row get changed?
Only two things move a row: reading the county's own document, or a call to the county logged with its date. Where a row says to confirm with the county, the county's site did not state the rule, and no one here filled the gap with a guess. Work for one of these counties and see a row that is wrong? Send the county's page to the address in the footer, and the row gets fixed and dated again.
Found your county in the table?
Asking is free and commits you to nothing. One independent builder receives your request. It is not sold to a lead list or sent to any other contractor.
Facts on this page last read September 13, 2026.