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

Unincorporated Austin County requires a development permit before a house, barn, or manufactured home is built or moved onto property¹. Residential projects must meet current platting and road-frontage requirements before permit documents are submitted, unless Commissioners Court approval is required⁸. The published residential development-permit fee is $100 outside a flood zone; flood-zone homes have a $200 base fee plus an enclosed-area surcharge, which Planning and Development should calculate¹¹. The county conducts a residential final inspection; the assigned 911 address and permits must be posted to avoid a reinspection fee¹. We could not confirm countywide building-code adoption or a residential certificate-of-occupancy requirement; ask Planning and Development what closeout applies. Bellville and Sealy have adopted municipal construction codes, which do not establish countywide code adoption^12,13.

Austin County Planning and Development accepts commercial, land-division, pipeline, right-of-way, and single-family applications at DebR@austincounty.com; septic and minor construction applications go to planning1@austincounty.com³. For county-administered development outside incorporated municipal jurisdiction, a pre-application meeting is required unless the County Engineer or designee waives it for a minor project or one with minimal infrastructure impact⁸. A compliant application goes to the next available Commissioners Court agenda for consideration, and approval requires an affirmative majority vote⁸. The county fee schedule controls over conflicting amounts in forms or regulations, and applicants pay outside engineering-review costs before plan or document approval¹¹.

Unincorporated Austin County has no county zoning rule setting minimum dwelling size, lot coverage, building height, tiny-home occupancy, or temporary-camping limits⁵. County subdivision and development controls still apply; special-district developments must follow county regulations when no development agreement with a city exists⁶. OSSF-served lots using public water or an individual well generally need at least 1 net acre⁶. New buildings in covered subdivisions or developments require front setbacks from the property line of 25 feet on non-thoroughfare roads or 50 feet on thoroughfares, outside more specific municipal rules⁶. Inside Sealy, municipal land-use standards apply; septic permitting still requires an approved plan and coordination with the local OSSF authority, Austin County Planning and Development^2,3,14.

Austin County requires an OSSF construction and location permit for an individual septic system serving a residence or business⁶. Austin County Planning and Development is the local permitting authority; email planning1@austincounty.com to begin³. The published conventional OSSF fee for a single-family residence is $275¹¹. A parcel may use an approved community sewage system or a properly designed and operational OSSF; a community connection is preferred where possible when it is less than 300 feet away⁶. The Town of San Felipe is a separate OSSF authority, so confirm its current filing contact⁴. Texas's 10-acre exemption applies only when every condition is met, including licensed evaluation and 100-foot separation from property lines; confirm local requirements with the OSSF authority before relying on it^6,14. Only 4.9% of Austin County soils are rated “not limited” for a conventional septic drain field; plan for a site evaluation and possibly an engineered system, rather than assuming septic is impossible¹⁵.

For an RV or tiny home on private land in unincorporated Austin County, ask Planning and Development how the proposed setup fits the county development-permit requirement before placing a structure¹. A manufactured-home application requires a recorded deed copy, assigned 911 address documentation, and the applicable fee¹. Off-grid sewage disposal must use a properly designed, operational OSSF that satisfies county septic requirements⁶. County-regulated RV parks have different rules: permanent residence and permanent fixtures are barred on individual spaces⁶. RV parks, manufactured-home communities, and multi-tenant developments also need an approved Infrastructure Development Plan before site improvements begin; county infrastructure inspections and a Certificate of Compliance concern those developments, not a general home-occupancy approval⁸.

1. Establish parcel jurisdiction: the unincorporated-county zoning answer does not cover Sealy municipal land-use standards or Bellville and Sealy construction codes^2,5,12,13.
2. Check plat status before designing the site; land divisions outside municipalities generally require a plat unless an exemption is approved, and municipal or extraterritorial-jurisdiction procedures may apply⁶.
3. Contact Planning and Development for the pre-application meeting and obtain the development permit before building or placing a house, barn, or manufactured home^1,8.
4. Apply for the OSSF permit through planning1@austincounty.com, or confirm the separate OSSF process with the Town of San Felipe if the parcel is there^3,4.
5. Obtain a floodplain permit in a flood hazard area and Bluebonnet Groundwater Conservation District authorization before drilling a domestic well^10,16.
6. Post the permit during construction, then post the assigned 911 address and permits for the county's final inspection^1,8.

Water: domestic wells in Austin County are exempt from a Bluebonnet Groundwater Conservation District operating permit but must register and require District authorization before drilling¹⁰. Flood: mapped flood-zone work requires an Austin County floodplain development permit¹⁶. Access: a new or reworked driveway onto a Texas state highway needs a TxDOT permit using Form 1058¹⁷. Agricultural divisions: an exemption outside municipal limits requires Commissioners Court approval and a County Engineer Certificate of Plat Exemption, OSSF minimum lot sizes, and direct roadway access without easement access; platting requirements immediately apply if the qualifying agricultural use ends⁶. Taxes: the effective property tax rate is about 1.3%, with a median annual bill near $3,464¹⁵.