Washington County, TX Building Permits, Zoning & Septic Rules

Unincorporated Washington County, Texas does not require a building or electrical permit for new construction or an addition to an existing structure¹. The county still requires separate permits for anything touching the floodplain, a driveway onto a county-maintained road, or a septic system, and Texas law gives Washington County no zoning authority at all²³. Washington County Engineering and Development Services handles driveway and floodplain permits, while its Environmental Health division handles septic permits⁴.

At a glance

Building permit: Not required for new construction or additions in unincorporated Washington County¹⁵
Zoning: None -- Texas law gives Washington County no zoning authority⁶³
Septic permit: Required for any new, altered, repaired or enlarged system, regardless of acreage⁷
Floodplain permit: Required before development in a mapped flood hazard area; $325 single-family / $425 non-profit / $525 multi-unit fee⁸⁹
Driveway (culvert) permit: Required for a driveway fronting a county-maintained road; $625 for 20-30 ft wide, $875 for 31-40 ft wide¹⁰⁹
RV / tiny home / manufactured home living: Unrestricted by county zoning³
Owner-builder: Allowed -- there is no county building permit to be exempt from¹¹¹²

Who to call

Roads & driveways

Washington County Engineering and Development Services (Road and Bridge)

Driveway/culvert permits, subdivision applications, utility-right-of-way permits, and road and bridge maintenance for unincorporated Washington County

979-277-6275

[email protected]

3650 State Highway 36 N, Brenham, TX 77833-3753

Septic permits

Washington County Environmental Health (Engineering and Development Services)

Septic (OSSF) and floodplain development permits for Washington County

979-277-6290

3650 Highway 36 North, Brenham, Texas 77833

Contact details are copied from each office’s official page and were checked against it on September 24, 2026.

Do you need a building permit in Washington County, Texas?

Unincorporated Washington County does not require a building or electrical permit for new construction or an addition to an existing structure¹. The county's own permit FAQ says so plainly: no building or electrical permits are required in unincorporated Washington County for a new build or an addition⁵. That does not clear every permit, though -- a floodplain permit, an OSSF (septic) permit, a driveway culvert permit, a utility-right-of-way permit, and a subdivision application or variance letter can each still apply depending on the project⁵. Outside a mapped flood hazard area, Texas law does not give most counties general building-code authority either: only a county with a population over 250,000, or one adjacent to such a county, may adopt a fire code covering commercial and larger residential buildings, and Washington County's population of about 37,007 falls well short of that mark¹³¹⁴.

Who handles building, driveway and floodplain permits in Washington County?

Washington County Engineering and Development Services issues driveway (culvert) permits, subdivision applications and utility-right-of-way permits, and its Road and Bridge division maintains county roads and bridges¹⁵. Reach that office at 979-277-6275, 3650 State Highway 36 N, Brenham, TX 77833-3753, or by email at [email protected]¹⁵. Washington County Environmental Health, a division of the same department, administers floodplain permits and septic (OSSF) permits and can be reached at 979-277-6290, 3650 Highway 36 North, Brenham, Texas 77833¹⁶¹⁷. Both offices share the same Highway 36 North complex in Brenham but handle different permits, so match your project to the right one before you call¹⁵¹⁶.

Does Washington County have zoning?

Washington County has no zoning ordinance, because Texas law gives zoning authority only to municipalities, not counties, outside a short list of specific, narrowly defined places elsewhere in the state⁶³. Because the county has no zoning authority, it sets no minimum lot size, setback, lot-coverage or building-height rule for unincorporated land, and accessory dwelling units are unrestricted by county zoning³. That absence of zoning is a real, confirmed answer here, not a gap in the county's paperwork -- Texas state law is what removes Washington County's zoning power³. Subdividing land is still regulated separately from zoning: dividing a tract into two or more parts outside an incorporated city requires a plat approved by the Washington County Commissioners Court, or a variance letter, even though no zoning applies¹⁸.

How do septic and floodplain permits work in Washington County?

Washington County Environmental Health administers on-site sewage facility (septic) permitting throughout the county, and every new, altered, repaired or enlarged system needs a permit before work begins, regardless of acreage -- only routine maintenance like tank pumping is exempt⁷. The county's OSSF fee schedule lists $325 for a single-family residential permit application, $425 for non-profit, and $525 for a multi-unit residential or non-residential system⁷. All septic construction must pass a county inspection before the system is covered, and you must call to schedule that inspection at least 24 hours in advance¹⁹. Because Washington County participates in the National Flood Insurance Program, a separate permit and written authorization are required before any development or construction touching the floodplain begins, at $325 for a single-family residential floodplain determination, $425 for non-profit, or $525 for multi-unit/non-residential⁸⁹. Only about 5.3% of Washington County's soils are free of severe limitations for a conventional septic drain field, among the more challenging counties for a standard drain field, so budget for a site evaluation and likely an engineered or aerobic system²⁰.

Can you live in an RV, tiny home or manufactured home on your land in Washington County?

Yes -- Washington County has no zoning authority, so RV occupancy, tiny-home occupancy and manufactured-home occupancy on private land are unrestricted by county zoning³. That is a real answer from Texas law, not just an absence of a county rule: state law gives Washington County no power to regulate these uses through zoning³. A driveway onto a county-maintained road still needs a culvert permit no matter what you plan to live in, and installing a septic system for any of these still needs an OSSF permit¹⁰⁷. If you rent the property short-term instead of living in it yourself, Washington County collects a 7% Hotel Occupancy Tax outside city limits, including on short-term rentals²¹.

Building on land in Washington County: the steps, in order

Confirm your parcel is not in a mapped flood hazard area; if it is, get a floodplain permit and written authorization from Washington County Environmental Health before work begins -- $325 for a single-family residence¹⁶⁸⁹.
No county building or electrical permit is required for the home itself in unincorporated Washington County⁵.
Apply for an OSSF (septic) permit through Environmental Health before installing a system -- $325 for a single-family residential application, with the inspection scheduled at least 24 hours in advance¹⁶⁷¹⁹.
If your driveway will front a county-maintained road, get a culvert permit from Engineering and Development Services -- $625 for 20-30 feet wide, $875 for 31-40 feet wide¹⁵⁹.
If you are dividing the tract into two or more parts outside a city, submit a plat or variance letter to the Commissioners Court, unless the land is used primarily for agriculture, ranching, wildlife management or timber production, which can qualify for the platting exemption¹⁸²².
Because Washington County has no zoning, there is no county setback, lot-size or building-height review to clear before you build³.

What to check before you buy land in Washington County

Washington County averages 43.7 inches of rain a year and has spent roughly 20.5% of years in severe drought, more rain than most of Texas but still worth confirming your water source²³²⁴. Only about 5.3% of the county's soils are free of severe limitations for a conventional septic drain field, even though all of the county's land sits at 15% slope or less, so flat ground here does not guarantee an easy septic site²⁰²⁵. Federal land covers only 2.6% of the county, so nearly all of Washington County is private²⁶. The county's effective property tax rate is about 1.1%, with a median property tax bill of $3,105 a year²⁷²⁸. Washington County sits roughly 27 miles from the nearest metro area, with a population density of 61.3 people per square mile -- close enough for a commute, denser than most rural counties in this index²⁹³⁰.

Watch-outs

Washington County requires no general building permit, but skipping the floodplain, septic or driveway culvert permit is still a real risk -- each is enforced separately from the building-permit exemption⁵.
Washington County's own pages do not state whether a building inspection, a certificate of occupancy, or a water-well permit applies here -- ask Engineering and Development Services or Environmental Health directly rather than assume either way¹⁵¹⁶.
Washington County Environmental Health and Engineering and Development Services share the same Highway 36 North complex in Brenham but use different phone lines -- call the septic/floodplain line for septic and floodplain questions, and the road/driveway line for culvert and subdivision questions¹⁶¹⁵.

Sources

Written September 24, 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.

How Washington County scores

Seclusion26100% ev.

Self-Sufficiency39100% ev.

Admin Boringness92100% ev.

Durability47100% ev.

Property Autonomy71100% ev.

Carry Cost69100% ev.

Evidence strength: 100%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$376kTypical home

1.1%Property tax

$4,646Land / acre

43.7"Annual rain

20.5% of yrsSevere drought

43.4 / yr (+29.3)Mid-century 100°F days

21.4 daysMid-century dry spell

2.58" (+6.7%)Mid-century 1-day rain

1.41×Wildfire change factor

100%Forward climate coverage

$2,884Home insurance / yr

3.4% / yrInsurance growth

0%Nonrenewal rate

county median (2+ published ZIPs)Insurance basis

24,172People within 30 min

10,449,378People within 2 hr

34,483Radius comparison (15 mi)

61.3People / sq mi

2.6%Federal land

100%Land at 15% slope or less

5.3%Septic soil without severe limits

17,663 acWorkable land screen

15.5%Wooded land

16.7 tonsBiomass / forest ac

68.6°FAvg temp

Answers from the rulebook for Washington County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

Washington County rules

Building permitNot required
New residential construction or additions to existing structures in unincorporated Washington County, Texas.
- A floodplain permit is required for building in the floodplain.
- An OSSF permit is required for installing, replacing, repairing, or adding to an OSSF septic tank.
- A culvert permit is required for installing a driveway fronting a county-maintained road.
- A utility installation permit is required for installing utilities in the county right-of-way.
- A subdivision application or variance letter is required for subdividing a tract of land.
- The page states only that no building or electrical permits are required; it does not eliminate other applicable permits or approvals.
“New build or adding on to an existing structure? No, no building or electrical permits are required in unincorporated Washington County.”
Washington County Engineering and Development Services ↗Re-checked Sep 23, 2026
Owner-builder exemption · follows from the permit answerNot needed
Unincorporated Washington County: no county building permit is required, so there is no permit to be exempt from and you may build your own home. State licensing for electrical, plumbing and HVAC work may still apply.
- A floodplain permit is required for building in the floodplain.
- An OSSF permit is required for installing, replacing, repairing, or adding to an OSSF septic tank.
“New build or adding on to an existing structure? No, no building or electrical permits are required in unincorporated Washington County.”
Washington County Engineering and Development Services ↗Re-checked Sep 23, 2026
Zoning districts · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Minimum dwelling size · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Minimum lot size · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Setbacks · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Lot coverage · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Building height · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Living in an RV · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Camping on your land · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Tiny homes · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Manufactured homes · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Accessory dwellings · by state lawNo county rule
Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us.
- Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
Who permits septicCounty
On-site sewage facility permitting throughout Washington County, Texas.
- Washington County Environmental Health is a division of Washington County Engineering and Development Services.
- Washington County operates under an OSSF Order authorized by the Texas Commission on Environmental Quality.
- Any amendments to the Washington County Order must be approved by TCEQ.
“We administer on-site sewage facility (septic system) permitting throughout Washington County.”
Washington County Environmental Health ↗Re-checked Sep 23, 2026
Septic permitRequired
New, altered, repaired, or enlarged septic systems in Washington County, Texas.
- The permit must be obtained before work begins.
- The requirement applies regardless of acreage.
- Routine maintenance such as tank pumping does not require a permit.
- The permit application, site evaluation, and design must be submitted for review and approval before written Authorization to Construct is issued.
- Current fee schedule retrieved September 23, 2026 is marked REV 2025-04: $325 for single-family residential, $425 for non-profit, and $525 for multi-unit residential or non-residential OSSF permit applications.
- Fees are non-refundable; a credit/debit card processing fee is charged when applicable.
single-family residential OSSF permit application fee: 325 USD (Current fee schedule marked REV 2025-04) · non-profit OSSF permit application fee: 425 USD (Current fee schedule marked REV 2025-04) · multi-unit residential or non-residential OSSF permit application fee: 525 USD (Current fee schedule marked REV 2025-04)
“All new, altered, repaired, or enlarged septic systems require a permit before work begins, regardless of acreage. Routine maintenance such as tank pumping does not require a permit.”
Washington County Environmental Health ↗Re-checked Sep 23, 2026
Septic inspectionRequired
Septic-system construction in Washington County, Texas.
- All work must pass inspection before the system is covered.
- Inspection must be scheduled at least 24 hours in advance.
- After a successful inspection, the county issues a Notice of Approval, meaning the system passed inspection and is approved for use.
- For aerobic systems, ongoing lifetime maintenance is required, maintenance reports are quarterly for single-family residences and monthly for commercial food establishments, and a maintenance tracking fee applies.
minimum advance inspection scheduling notice: >= 24 hours · aerobic-system maintenance report frequency for single-family residences: per quarterly · aerobic-system maintenance report frequency for commercial food establishments: per monthly · OSSF re-inspection fee: 150 USD (Current fee schedule marked REV 2025-04)
“All septic system construction must be inspected by a Washington County Environmental Department Inspector. All work must pass inspection before the system is covered. Call to schedule an inspection at least 24 hours in advance.”
Septic System Permitting Procedures ↗Re-checked Sep 23, 2026
Agricultural exemptionAvailable (with conditions)
Exemption from the requirement to plat a land division outside the platting jurisdiction of an incorporated town or city in Washington County when the land is used primarily for agricultural, farm, ranch, wildlife-management, or timber-production purposes.
- The owner must divide a tract into two or more parts.
- The owner must not intend to lay out any part of the land for streets, alleys, squares, parks, or other parts dedicated for public use.
- The land must be used primarily for agricultural uses, or for farm, ranch, wildlife management, or timber production use.
- The exemption does not release the subdivider from minimum lot frontage, minimum setback, or minimum lot area requirements.
- Washington County requests, though does not require, a courtesy notification letter; a survey or sketch would be helpful.
- If any daughter lot loses exemption status or no longer qualifies for the exemption originally used, all related landowners must plat the entirety of the parent tract.
- The regulations state that the exemption is under Texas Local Government Code Section 232.0015(D).
agricultural-use threshold: used primarily for agricultural, farm, ranch, wildlife management, or timber production
“The land is used primarily for agricultural uses, or for farm, ranch, wildlife management, or timber production use.”
Washington County Subdivision and Development Regulations ↗Re-checked Sep 23, 2026
Subdividing landRegulated (with conditions)
Subdivision of a tract into two or more parts outside the boundaries of an incorporated town or city in Washington County, Texas.
- A plat must be prepared and submitted for approval by the Washington County Commissioners Court under Section 3.01.
- The regulations apply to subdivisions, additions, lots, roads, alleys, squares, parks, or other parts intended for public use or for use by purchasers or owners of lots.
- A subdivision for which the Commissioners Court received a preliminary plat before the regulations' effective date is governed by the regulations in effect when the plat was submitted.
- Incorporated municipalities and their platting jurisdictions may have separate requirements; where no interlocal agreement exists, both the municipality and Washington County must approve development, with final approval by the County.
- A subdivision application or variance letter is required according to the County's Engineering and Development Services page.
minimum division size: two or more parts
“Subdividing a tract of land? Yes, a subdivision application or variance letter is required.”
Washington County Subdivision and Development Regulations ↗Re-checked Sep 23, 2026
Driveway accessRequired
A driveway fronting a county-maintained road in Washington County's unincorporated areas.
- The county road page specifies a culvert permit; the cited source does not establish a county permit requirement for driveways fronting state-maintained roads.
- Washington County's addressing page states that whether a culvert is needed depends on whether the entrance is from a county-maintained road or a state-maintained road.
“Installing a driveway fronting a county-maintained road? Yes, a culvert permit is required.”
Washington County Engineering and Development Services ↗Re-checked Sep 23, 2026
Building in a floodplainRequired
Development or construction relating to the floodplain on property in unincorporated areas of Washington County.
- A permit and authorization are required before floodplain-related development or construction begins.
- The permit application, fee, and planning materials must be submitted for review and authorization before work begins.
- Work may not begin before written authorization or an exemption.
- If the proposed development is not located in a Special Flood Hazard Area, it is exempt from Washington County standards for development in a Special Flood Hazard Area.
- If development exceeds 50 lots or 5 acres, whichever is less, base flood elevation data must be provided.
- Additional state and federal permits may apply to wetlands.
base flood elevation data threshold: more than 50 lots or 5 acres, whichever is less
“Because Washington County participates in the National Flood Insurance Program, a permit and authorization are required before any development/construction relating to the floodplain begins.”
Washington County Environmental Health ↗Re-checked Sep 23, 2026
Short-term rentalsLimited
Compliant short-term rentals outside Washington County city limits.
- Washington County charges a 7% Hotel Occupancy Tax that includes short-term rentals.
- The tax is collected quarterly.
- The county handles hotel occupancy tax matters outside city limits; the city handles matters within city limits.
- The county page states that compliant short-term rentals are registered with the Chamber of Commerce and the State of Texas.
hotel occupancy tax: 7 percent (Includes short-term rentals; collected quarterly)
“In 2010, Washington County elected to charge a 7 % Hotel Occupancy Tax (which includes short-term rentals). This tax is collected quarterly.”
Hotel Occupancy Tax Information ↗Re-checked Sep 23, 2026
Permit feesPublished (with conditions)
County Engineering and Development Services permits, including driveway, floodplain determination, OSSF/septic, subdivision development, utility-right-of-way, and prescribed-burn permits.
- The fee schedule lists residential driveway fees of $625.00 for 20–30 feet wide and $875.00 for 31–40 feet wide.
- The fee schedule lists culvert extension at $50 per linear foot, commercial driveway over 40 feet wide at $150.00, and inspection with no culvert required at $50.00.
- The fee schedule lists floodplain determination permit fees of $325.00 for single-family residential, $425.00 for non-profit, $525.00 for multi-unit/non-residential, and $75.00 for a benchmark disc.
- The fee schedule states that a processing fee is charged to all credit/debit card payments and paid directly to Certified Payments.
residential driveway fee, 20-30 feet wide: 625 USD · residential driveway fee, 31-40 feet wide: 875 USD · culvert extension: 50 USD per linear foot · floodplain determination permit, single-family residential: 325 USD · floodplain determination permit, non-profit: 425 USD · floodplain determination permit, multi-unit/non-residential: 525 USD
“Floodplain Determination Permit Single-Family Residential $325.00 Non-Profit $425.00 Multi-Unit /Non-Residential $525.00 Benchmark Disc $75.00”
Washington County Engineering and Development Services Fee Schedule ↗Re-checked Sep 23, 2026
Permit processPublished (with conditions)
County-administered floodplain, driveway, septic, utility-right-of-way, subdivision, and related permits in Washington County, with the cited floodplain rule expressly applying to unincorporated areas.
- Washington County provides an online process for septic, floodplain, and prescribed-burn permits.
- Floodplain applications, fees, and planning materials must be submitted for review and authorization before work begins.
- For floodplain development, work may not begin before written authorization or exemption.
- A driveway fronting a county-maintained road requires a culvert permit.
- New construction or additions in unincorporated Washington County do not require county building or electrical permits, according to the county's permit FAQ.
“To apply for Septic Permits, Floodplain Permits, and Prescribed Burn Permits, please use our new online process.”
Washington County Environmental Health ↗Re-checked Sep 23, 2026
County-wide zoningAbsent
Under Texas law only municipalities, not counties, may adopt zoning; Washington County has no zoning in its unincorporated areas.
Washington County Engineering & Development Services ↗Scouted from the county site, not yet independently re-checked

Texas rules that apply here

Building code adoptedPartial
Industrialized housing and buildings, modules, and modular components governed by the Texas Industrialized Housing and Buildings program.
- The mandatory state code adoption applies to industrialized housing and buildings, modules, and modular components, not all construction statewide.
- The effective date is July 1, 2024.
- The International Existing Building Code applies to alterations of portable industrialized buildings.
- Manufacturers already certified for Texas must have design-package documents reviewed and approved to the new editions with an approval date on or after July 1, 2024, unless the manufacturer elected to transition before the effective date under Department rule 70.70(a)(5)(B).
- Construction begun on or after July 1, 2024 must comply with the new code editions and approved design packages.
- Construction begun before July 1, 2024, or before a manufacturer's effective transition date, must meet the stated completion, inspection, and labeling deadline to remain eligible for a Texas decal.
effective date: 2024-07-01 · International Building Code: 2021 Edition (including appendices C, F, and K) · International Residential Code: 2021 Edition (including appendices AG, AH, AK, AP, AQ, and AT) · International Fuel Gas Code: 2021 Edition · International Mechanical Code: 2021 Edition · International Plumbing Code: 2021 Edition · International Energy Conservation Code: 2015 Edition · National Electrical Code: 2020 Edition · International Existing Building Code: 2021 Edition (for alterations of portable industrialized buildings)
“July 1, 2024, all industrialized housing and buildings, modules, and modular components shall comply with the following codes, as amended in §70.101 of the IHB Rules:”
Industrialized Housing and Buildings – Adoption of New Code Editions ↗Re-checked Sep 12, 2026
county zoning authorityLimited
Texas counties adopting zoning regulations for specified unincorporated or otherwise specially defined areas.
- Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters.
- For Padre Island, the authority applies in Cameron or Willacy County outside a municipality and within two miles of a publicly owned park or recreational development, or within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.
- Other Chapter 231 subchapters address special areas including the Amistad Recreation Area in Val Verde County, military zones, certain lakes, the El Paso Mission Trail Historical Area, Lake Somerville, and Falcon Lake in Zapata County.
- The cited statute was enacted effective September 1, 1987; the Falcon Lake subchapter was added effective June 15, 2007, and amended effective September 1, 2009.
Padre Island distance from publicly owned park or recreational development: <= 2 miles (Area must be outside a municipality and in Cameron or Willacy County.) · Padre Island distance from beach, wharf, or bathhouse: <= 2 miles (The beach, wharf, or bathhouse must be used by at least 500 persons annually.)
“This subchapter applies to the areas of Padre Island located in Cameron or Willacy County and located: (1) outside a municipality but within two miles of a publicly owned park or recreational development; or (2) within two miles of a beach, wharf, or bathhouse used by at least 500 persons annually.”
Local Government Code Chapter 231, County Zoning Authority ↗Re-checked Sep 21, 2026
county building authorityLimited
Texas counties adopting and enforcing fire-code building permits for specified buildings in unincorporated areas and applying residential building-code standards in certain counties.
- Under Section 233.061, the county must have a population over 250,000 or be adjacent to a county with a population over 250,000.
- Under Section 233.062, the fire code applies only to commercial establishments, public buildings, and multifamily residential dwellings consisting of four or more units constructed in an unincorporated area.
- The fire code does not apply to an industrial facility having a fire brigade that conforms to Occupational Health and Safety Administration requirements.
- A covered applicant must submit a plan and a commissioners-court-set application fee; the county must issue or deny the permit within 30 days, and failure to act within 30 days approves the construction for purposes of the subchapter.
- The fire code must conform to the International Fire Code or Uniform Fire Code as those codes existed on May 1, 2005, or establish protective measures exceeding those standards; later editions may be adopted.
- Residential standards under Section 233.152 apply only if the county adopts a resolution or order and the county is within 50 miles of an international border or has a population over 100.
- Those residential standards apply only to new single-family-house or duplex construction beginning after September 1, 2009; manufactured or modular structures governed by Occupations Code Chapters 1201 or 1202 are excluded from the definition of new residential construction.
- A municipality's building code controls in its extraterritorial jurisdiction, and Section 233.152 does not authorize county prior approval of new residential construction or county zoning regulations.
- Fire-code inspection and permit fees may be charged under a fee schedule based on building type, limited to amounts necessary to administer and enforce the subchapter; inspection fees must be reasonable and reflect approximate inspection costs.
county population threshold for fire-code authority: > 250000 persons (A county adjacent to a county over 250,000 also qualifies.) · multifamily residential dwelling threshold: >= 4 units (The fire code applies only to covered buildings constructed in an unincorporated area.) · residential-code border distance: <= 50 miles (Alternative qualification is county population over 100.) · application decision period: 30 days (If the commissioners court does not issue or deny the permit within 30 days after receiving the application and fee, construction is approved for purposes of the subchapter.) · residential standards effective construction date: > 2009-09-01 (Applies only to new residential construction that begins after September 1, 2009.)
“The commissioners court of a county with a population of over 250,000 or a county adjacent to a county with a population of over 250,000 may adopt a fire code and rules necessary to administer and enforce the fire code. [...] The fire code applies only to the following buildings constructed in an unincorporated area of the county: (1) a commercial establishment; (2) a public building; and (3) a multifamily residential dwelling consisting of four or more units.”
Local Government Code Chapter 233, County Regulation of Housing and Other Structures ↗Re-checked Sep 21, 2026

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

Inspections — Building inspections for residential construction in unincorporated Washington County, Texas.
Certificate of occupancy — Certificates of occupancy for residential construction in unincorporated Washington County, Texas.
Off-grid sanitation — Off-grid sanitation arrangements in Washington County, Texas, including arrangements other than permitted on-site sewage facilities.
Well permit — Water-well permit or registration requirements in Washington County, Texas.
Mandatory utility hookup — Water and sewer utility-connection requirements in Washington County, Texas.

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Living off-grid in Washington County, Texas

Is Washington County a good place to live off-grid or homestead?

Washington County scores 52/100 on the Bolthole Index, a solid county profile. Its strengths: low administrative friction for a quiet rural property and a stronger property-autonomy legal backdrop. Watch-outs: sparse surroundings — about 24,172 people within a 30-minute drive and workable self-sufficiency basics (43.7″/yr rainfall).

Do you need a building permit in Washington County, Texas?

Washington County does not require a county building permit for a home in unincorporated areas, and it has no county-wide zoning. Onsite septic is permitted by Washington County Environmental Health. Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

Can you live in an RV or tiny home on your land in Washington County?

Living in an RV on your own land in Washington County is allowed: Unincorporated Washington County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Washington County has no zoning ordinance. The county legal census found no county zoning ordinance, citing co.washington.tx.us. Septic, floodplain, subdivision and health rules still apply; cities and towns set their own rules inside their limits. Chapter 231 does not grant a general statewide county zoning power; authority is provided through geographically or subject-matter limited subchapters. A tiny home is allowed. Confirm with the county before relying on it.

How much does land cost in Washington County, Texas?

Land in Washington County runs about $4,646 per acre, based on the latest county data.

What is the water situation in Washington County?

Washington County gets about 43.7" of rain a year, with severe drought in roughly 20.5% of years.

How remote is Washington County?

A representative private-land location has about 24,172 people within a 30-minute drive and 10,449,378 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

Building permits, zoning and septic rules in Washington County, Texas

At a glance

Who to call

Do you need a building permit in Washington County, Texas?

Who handles building, driveway and floodplain permits in Washington County?

Does Washington County have zoning?

How do septic and floodplain permits work in Washington County?

Can you live in an RV, tiny home or manufactured home on your land in Washington County?

Building on land in Washington County: the steps, in order

What to check before you buy land in Washington County

Watch-outs

Sources

Washington County in Texas

How Washington County scores

Find land. Bring the promising ones back.

Parcel due diligence

Answers from the rulebook for Washington County

Washington County rules

Texas rules that apply here

Still unanswered

Living off-grid in Washington County, Texas

Is Washington County a good place to live off-grid or homestead?

Do you need a building permit in Washington County, Texas?

Can you live in an RV or tiny home on your land in Washington County?

How much does land cost in Washington County, Texas?

What is the water situation in Washington County?

How remote is Washington County?

How Washington compares in Texas