Building permits, zoning and land rules in Gonzales County, Texas

Unincorporated Gonzales County has no general building-permit program². The county's own zoning and permitting letter tells builders exactly what construction in unincorporated areas needs: floodplain permits where they apply, septic permits when necessary, and driveway permits when a new drive connects to a county road, with no general building permit listed among them¹. Fire permits and plan reviews are required only for a commercial building or a rental community¹. Gonzales County does not issue certificates of occupancy unless one is requested as part of a fire-code inspection¹. None of this reaches property inside the City of Gonzales, where the city has adopted building codes and requires an application to its Building Official before construction⁴. We could not confirm whether a city's rules extend into its extraterritorial jurisdiction, so ask the city if your land is near its edge.

Floodplain, septic, driveway, subdivision-exception and fire permits for unincorporated Gonzales County all run through one office: the Gonzales County Permit Office at 1811 Water Street, Gonzales, TX 78629, phone (830) 672-6209, email permits@co.gonzales.tx.us⁹. The county has no separate building department or zoning office to contact². If your access comes off a state highway rather than a county road, contact the Texas Department of Transportation instead: TxDOT requires its own Form 1058 driveway permit and 24 hours' notice before construction starts in the highway right-of-way¹⁰. Inside the City of Gonzales, contact the city's Building Official for building permits instead of the county⁴.

There are no zoning regulations for the unincorporated areas of Gonzales County, according to the county's own zoning and permitting letter¹. Texas gives counties zoning power only in narrowly defined situations, and Gonzales County has not been given general zoning power⁵. That leaves unincorporated Gonzales County with no minimum lot size, setback, lot-coverage, building-height or minimum-dwelling-size rule, and no zoning restriction on an accessory dwelling, manufactured home or tiny home⁵. Inside the City of Gonzales, zoning applies instead: the city is divided into zoning districts to guide growth and land use¹¹. Whether city zoning reaches the city's extraterritorial jurisdiction is not confirmed, so ask the city before assuming it does not. Land divided into lots outside city limits still needs a subdivision plat approved by the Commissioners Court, or an approved exception, even though no zoning applies¹².

The Gonzales County Permit Office administers septic (OSSF) permits directly as the TCEQ-authorized local agent, rather than sending applicants to the state^3,9. Before you can get a permit, the office performs a site evaluation of the property to determine soil type and suitability³. Permit fees run $310 for a conventional system, $410 for an aerobic or engineered system, and $510 for a commercial or industrial system, and the office processes applications in 5 to 7 working days once it has everything it needs³. A finished system still needs an inspection showing it was installed to TCEQ construction standards before the county issues a permit to operate³. Texas's statewide 10-acre rule can exempt a single-family home from OSSF permitting entirely if the tract is at least 10 acres, the home is the only dwelling on it, every part of the system sits at least 100 feet from the property line, and a licensed evaluator confirms the other conditions⁸. Soil here works against the conventional option either way: fewer than 8% of Gonzales County's soils carry no severe limitation for a standard drain field, so plan on the possibility of the pricier aerobic system¹³. An engineer or registered sanitarian must design the system on Type 1a or Type IV soil, on floodplain sites and in subdivisions restricted to engineered systems, and the permit review asks for an approved 911 address, proof of ownership and a driveway permit, plus a septic affidavit and maintenance contract for aerobic systems³.

Outside city limits, no county zoning ordinance restricts RV, travel-trailer or tiny-home occupancy on unincorporated Gonzales County land, and the county's own letter confirms it has no zoning regulations there at all^1,5. A driveway serving the property still needs a county driveway permit if it connects to a county road, including for a use the county classifies as a mobile-home or RV park, which carries its own $400 fee⁶. If the site sits in the mapped floodplain, only parking, access and storage are allowed below the base flood elevation, so a floodplain parcel is a poor fit for ground-level RV living without a permitted, elevated setup⁷. None of this reaches property inside the City of Gonzales, which regulates through its own zoning districts¹¹.

1. Confirm the parcel sits outside the City of Gonzales and any other municipality's limits, and ask a nearby city whether its rules reach into its extraterritorial jurisdiction; unincorporated land has no county zoning or general building permit^1,2.
2. Contact the Gonzales County Permit Office to check whether the parcel is in the mapped floodplain and needs a floodplain development permit before you build^7,9.
3. Apply for a driveway permit with the Permit Office if your access comes off a county road. A permit is needed for a new driveway, a culvert, changing dirt to concrete or asphalt, or widening, but not for adding gravel to an existing gravel driveway⁶. Bring the application, a map of the proposed driveway, and the fee before any work starts⁶.
4. Get a site evaluation and apply for your OSSF permit before you site the house, since soil results determine whether a conventional or aerobic system is allowed^3,13.
5. File a subdivision plat, or an Affidavit of Land Location & Exception if the tract qualifies, with the Commissioners Court before dividing or selling part of the property; the exception application fee is $100 and non-refundable, and land used primarily for agriculture, ranching, wildlife management or timber production may qualify¹².
6. Schedule your septic inspection once the system is installed; the county issues a permit to operate only after confirming the system meets TCEQ construction standards³.
7. Gonzales County does not require a certificate of occupancy unless you request one as part of a fire-code inspection, which applies mainly to commercial buildings and rental communities¹.

Budget for a harder septic system: fewer than 8% of Gonzales County's soils carry no severe limitation for a conventional drain field, so an aerobic system near $410 rather than a $310 conventional one is a realistic outcome^3,13. The county sits in a region that spends roughly 23% of years in severe drought and gets under 35 inches of rain annually, so confirm a well or rural water access before you commit¹³. All of the county's land sits at 15% slope or less, which is favorable for building and septic siting on most parcels, but a site-specific soil test still decides your system type¹³. If the parcel is near a creek or low area, ask the Permit Office whether it sits in the mapped floodplain before you buy, since that adds a separate development permit and limits any living space below the base flood elevation⁷. Gonzales County's effective property tax rate runs about 1.2%, with a median annual bill near $1,949¹³.