Unincorporated Tom Green County, Texas has no building-permit program and no zoning ordinance, because the county's adopted authority covers only subdivision platting, OSSF/septic, roads/drainage, and floodplain development, and Texas counties aren't given general building or zoning power in unincorporated areas12. Septic systems are handled separately through Tom Green County Environmental Health, the TCEQ-authorized agent, which permits and inspects every on-site sewage facility outside incorporated cities like San Angelo3. The county does regulate specific activities: septic, floodplain development, driveway and road-cut access, and subdivision or manufactured-home-rental-community platting456.
At a glance
- Building permit
- Not required in unincorporated Tom Green County; the county's authority covers only septic, floodplain, roads/drainage, and subdivision platting1
- Zoning
- None countywide; only the incorporated City of San Angelo has its own zoning ordinance and Zoning Board of Adjustment27
- Septic permits
- Tom Green County Environmental Health, the TCEQ-authorized agent; every OSSF must be permitted and inspected, with no exemption for tracts of 10 acres or more389
- Floodplain permit
- Required for new development and substantial improvements in regulated, mapped floodplains, administered by Environmental Health4
- Driveway / road-cut permit
- Required through the county precinct commissioner; $100 for commercial driveway access, $500 for a county road cut, valid one year510
- RV / tiny home / minimum home size
- Unrestricted by county zoning outside a platted subdivision or manufactured-home rental community, since the county has no zoning ordinance11
- Manufactured home rental communities
- Need a county-approved Infrastructure Development Plan before construction, with at least 60 feet of public-road frontage; utilities can't connect without a county Certificate of Compliance1213
- Septic soil difficulty
- Only 5% of county soils are free of severe limits for a conventional septic drain field14
Who to call
Septic permits
Tom Green County Environmental Health
OSSF (septic) permits and inspections, and floodplain development permits, for unincorporated Tom Green County
Edd B. Keyes Building, 1st Floor, 113 W Beauregard Ave, San Angelo, Texas 76903
Also useful
Tom Green County Clerk, Real Estate Section
Receives payment and completed applications for driveway access and county road-cut permits, and files approved subdivision plats and manufactured-home-rental-community applications
Contact details are copied from each office’s official page and were checked against it on September 23, 2026.
Do you need a building permit in Tom Green County, Texas?
No. Unincorporated Tom Green County's own adopted regulations enumerate its authority as subdivision platting, OSSF/septic, roads and drainage, and floodplain development only — there's no building-permit power listed anywhere in that authority, and Texas counties aren't given general power to require one in unincorporated areas1. An ordinary single-family home, cabin, barn, or shop outside those specific categories doesn't go through a county building-permit review. Three county permits can still apply to a given parcel: an OSSF permit if you need septic, a floodplain development permit if you're in a regulated, mapped floodplain, and a driveway or road-cut permit if you're accessing a county road945. Inside the incorporated City of San Angelo, the picture is different: the city has adopted the 2021 International Building and Residential Codes and administers its own zoning through a Zoning Board of Adjustment, so land inside city limits follows municipal rules, not the county's157.
Who handles permits in Tom Green County, and how do you reach them?
For septic and floodplain permits, contact Tom Green County Environmental Health at the Edd B. Keyes Building, 1st Floor, 113 W Beauregard Ave, San Angelo, Texas 76903, 325-658-103816. For a driveway access or county road-cut permit, the application goes to your precinct commissioner for a site visit, and the completed, approved permit and payment are then turned in to the Tom Green County Clerk's Real Estate Section175. Subdivision plats and manufactured-home-rental-community Infrastructure Development Plans also go through that same Real Estate Section process before Commissioners Court approval and filing1718. If your land instead sits within the City of San Angelo's extraterritorial jurisdiction under its annexation plan, the county directs applicants to file with the City of San Angelo Planning Department instead19.
Does Tom Green County have zoning?
No. Tom Green County's regulatory authority — subdivision platting, OSSF, roads and drainage, and floodplain — does not include zoning, and Texas law gives counties zoning power only for a handful of specially defined areas that don't include Tom Green County220. Land is unzoned countywide outside cities like San Angelo, which runs its own zoning ordinance and Zoning Board of Adjustment for property inside city limits7. What the county does regulate outside incorporated cities is subdivision development: a final plat or replat is required whenever land is divided into two or more parts or laid out with streets, alleys, or other shared-use areas, with an exception for agricultural, ranch, wildlife-management, or timber-production daughter tracts larger than 100 acres6. Subdivided lots served by a public water supply need at least a half-acre lot, and a subdivision is capped at 200 homes unless the Commissioners Court grants a variance21. Because there's no zoning ordinance, the county otherwise sets no minimum home size, no general minimum lot size, and no building-height limit11.
How do septic permits work in Tom Green County?
Every on-site sewage facility in Tom Green County, outside incorporated cities and areas already regulated under an existing rule, must be permitted and inspected by Environmental Health, the county's TCEQ-authorized agent38. Unlike some Texas counties, Tom Green County does not exclude properties of 10 acres or larger from its permitting process — every OSSF here needs a permit and inspection regardless of tract size9. That's a meaningful departure from the statewide default, where Texas otherwise allows a narrow 10-acre exemption if a licensed site evaluator signs off and several other conditions are met22. Soils make this more than paperwork: only 5% of Tom Green County's land is free of severe limitations for a conventional drain field, so plan on a site evaluation early and expect many properties to need an aerobic or alternative system14. The OSSF inspector who signs off must be TCEQ-certified, and a permit to operate is issued only after the installed system passes inspection23.
Can you live in an RV or tiny home on your land in Tom Green County?
Outside a platted subdivision or manufactured-home rental community, Tom Green County has no zoning ordinance restricting RV or tiny-home living, so there's no general county permit or minimum-size rule for an individual parcel11. RV parks and manufactured-home rental communities are a different matter: the county treats them as a Manufactured Home Rental Community, requiring a Commissioners-Court-approved Infrastructure Development Plan with at least 60 feet of frontage on a dedicated public street before construction can begin, and utilities can't connect until the owner provides a county-issued Certificate of Compliance1213. If your land is in the City of San Angelo's ETJ annexation-plan area, that kind of development is filed with the City of San Angelo Planning Department instead of the county19. Septic, subdivision, and floodplain requirements still apply to any RV park or rental-community development regardless of which office reviews it19.
Building a home in Tom Green County: the steps, in order
First, check FEMA flood maps for your parcel; if it's in a regulated, mapped floodplain, apply for a floodplain permit through Environmental Health before construction164. Second, order a septic site evaluation early, since only 5% of the county's soils are free of severe limitations for a conventional drain field14. Third, apply for your OSSF permit through Environmental Health; there's no exemption for larger tracts here, so this step applies regardless of acreage169. Fourth, if the land was recently divided from a larger tract, confirm it went through the county's subdivision-plat process, or qualified for the agricultural exception for daughter tracts over 100 acres6. Fifth, if your driveway will access a county-maintained road, apply through your precinct commissioner for a driveway access permit, budgeting $100 for commercial access or $500 for a road cut, and submit payment to the County Clerk's Real Estate Section1710. If your driveway instead connects to a state highway, apply to TxDOT using Form 1058 and give 24-hour notice before work begins24. Finally, build: an ordinary single-family home outside these specific county permit categories has no county building-permit review to schedule1.
What to check before you buy land in Tom Green County
Water and soils go together here: annual precipitation runs about 22.6 inches a year, one of the drier counties in this guide series, with 18.3% of years bringing severe drought, and only 5% of soils free of severe septic limitations252614. The land is flat and largely open — 97.5% sits at 15% slope or less, and only 7.4% is wooded — which makes finding a building site easy but offers little natural shade or windbreak2728. Check FEMA flood maps before you buy, since floodplain status drives the county's clearest permit requirement4. If the tract you're buying was recently divided or is part of a manufactured-home rental community, confirm it went through the county's subdivision or Infrastructure Development Plan process, since that affects road frontage, utility hookups, and whether a Certificate of Compliance was issued613. Typical property tax runs about 1.4% effectively, with a median bill near $2,523 a year, against a typical home value around $234,188293031.
Watch-outs
- No official Tom Green County source located for this guide states an owner-builder exemption, a certificate-of-occupancy requirement, or a general residential building-inspection schedule; confirm directly with Environmental Health before assuming a rule either way32.
- Tom Green County does not exempt 10-acre-or-larger tracts from septic permitting, unlike the statewide default some buyers expect from other Texas counties — budget for an OSSF permit regardless of how large your tract is9.
- Short-term rentals in unincorporated Tom Green County aren't addressed by any official county source found for this guide; confirm directly with the county before assuming a use is allowed1.
Sources
- Tom Green County Subdivision Regulations (2026 county census)
- Tom Green County Subdivision Regulations (2026 county census)
- Tom Green County Environmental Health (2026 county census)
- Environmental Health, quoted and re-checked
- Driveway Access/Road Cut Permit, quoted and re-checked
- TOM GREEN COUNTY SUBDIVISION REGULATIONS, quoted and re-checked
- Zoning Board of Adjustment, quoted and re-checked
- Tom Green County Environmental Health, quoted and re-checked
- Order Adopting Rules of Tom Green County, Texas for On-Site Sewage Facilities, quoted and re-checked
- Driveway Access/Road Cut Permit, quoted and re-checked
- Texas law on county zoning and building authority
- Tom Green County Manufactured Home Rental Community Development Regulations, quoted and re-checked
- TGC Manufactured Home Rental Community Development Regulations, quoted and re-checked
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- Codes & Regulations, quoted and re-checked
- Tom Green County Environmental Health (tomgreencountytx.gov)
- Tom Green County Clerk, Real Estate Section (tomgreencountytx.gov)
- Subdivision of Land/Manufactured Home and Rental Community Application Form, quoted and re-checked
- Tom Green County Subdivision of Land/Manufactured Home and Rental Community Application Form, quoted and re-checked
- Local Government Code Chapter 231, County Zoning Authority (Texas statewide rule), quoted and re-checked
- TOM GREEN COUNTY SUBDIVISION REGULATIONS, quoted and re-checked
- Getting a Permit for an OSSF - Such as a Septic System (Texas statewide rule), quoted and re-checked
- Order Adopting Rules of Tom Green County, Texas for On-Site Sewage Facilities, quoted and re-checked
- Section 4: Driveway Permits, Design, and Materials (Texas statewide rule), quoted and re-checked
- Annual precipitation: Bolthole Index county data
- Share of years in severe drought: Bolthole Index county data
- Share of land at 15% slope or less: Bolthole Index county data
- Wooded share of land: Bolthole Index county data
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
- Typical home value (Zillow): Bolthole Index county data
- (2026 county census)
Written September 23, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.