McMullen County, TX Building Permits, Zoning & Septic Rules

Q: Does McMullen County have zoning?

McMullen County has no zoning ordinance. Texas law gives county zoning authority only in a short list of specific, narrowly defined places elsewhere in the state, and McMullen County is not one of them, so the county has no legal power to zone. 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 zoning. That is a real, confirmed answer here rather than a gap in the county's paperwork -- Texas state law is what removes McMullen County's zoning power, not an unfinished ordinance.

McMullen County, Texas has no general building permit for a home, but new construction within a mapped flood hazard area needs a floodplain development permit returned to the County Judge's office¹². McMullen County also has no zoning ordinance, and Texas law gives it no legal power to adopt one, so land use, RV living, tiny homes, setbacks and minimum lot size are unrestricted by county zoning here³. Any new septic system still needs a permit through the county's OSSF program⁴.

At a glance

Building permit: Not required countywide; a floodplain development permit applies only in a mapped flood hazard area ($50 single-family / $300 commercial per the county's published fee schedule)¹⁵
Zoning: None -- Texas law gives McMullen County no zoning authority⁶³
Septic permit: Required for new OSSF systems, through the county's OSSF program⁴⁷
RV / tiny home living: Unrestricted by county zoning, since the county has no zoning authority³
Setbacks / minimum lot size: None published -- no county zoning authority sets these³
Well permit: Exempt under the McMullen Groundwater Conservation District if production stays under 25,000 gallons a day⁸
Driveway onto a highway or FM road: TxDOT permit (Form 1058) required; the county page does not require a permit for driveways onto county or private roads⁹

Who to call

Floodplain permits

McMullen County Judge's Office (County Court)

Floodplain development permit applications for McMullen County, and general county administration

361-274-3900

[email protected]

501 River Street, Tilden, Texas 78072

Septic permits

McMullen County OSSF Program

On-site sewage facility (OSSF / septic) permit applications and inspections for McMullen County

361-449-8043

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 McMullen County, Texas?

McMullen County has no general countywide building permit for a home¹. New construction, additions, relocations, demolitions, replacements and manufactured-home placement within, partially within, or adjacent to a mapped area of special flood hazard do need a floodplain development permit, returned to the County Judge's office¹⁰. The county's published floodplain fee schedule lists $50 for a single-family residence and $300 for commercial, industrial or other activity⁵. Outside a mapped flood hazard area, Texas law does not give most counties general building-code authority: only a county with a population over 250,000, or one adjacent to such a county, may adopt a fire code covering commercial buildings and larger residential buildings¹¹. McMullen County's population is about 568 people, far below that threshold, so this state authority does not reach it¹².

Who handles floodplain and permit questions in McMullen County?

The McMullen County Judge's office administers floodplain development permits, and the county's own materials name this office as where a flood-zone application is returned¹³². Reach the office at 361-274-3900, 501 River Street, Tilden, Texas 78072¹³. McMullen County has no separate building, zoning or planning department -- for anything outside floodplain development and OSSF (septic) permitting, ask the County Judge's office directly, since county materials do not name a different permitting office¹³.

Does McMullen County have zoning?

McMullen County has no zoning ordinance⁶. Texas law gives county zoning authority only in a short list of specific, narrowly defined places elsewhere in the state, and McMullen County is not one of them, so the county has no legal power to zone³. 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 is a real, confirmed answer here rather than a gap in the county's paperwork -- Texas state law is what removes McMullen County's zoning power, not an unfinished ordinance³.

How do septic permits work in McMullen County?

McMullen County requires a permit to construct, install, alter, extend or repair an on-site sewage facility (OSSF), administered through the county's OSSF program⁷. The permitting authority may enter the property to evaluate the lot and inspect the system, and a permit to operate is granted only after a successful inspection¹⁴. Reach the McMullen County OSSF program at 361-449-8043¹⁴. Texas's statewide 10-acre rule can remove the permit requirement for a single-family home: the tract must be 10 acres or larger, every part of the OSSF must sit at least 100 feet from the property line, effluent must stay on the property, and the home must be the only dwelling on the tract⁷. An emergency repair, such as replacing a tank lid or an inlet or outlet device, does not need a permit but must be reported in writing within 72 hours after the repair begins⁷. About 33.3% of McMullen County's soils are free of severe limitations for a conventional septic drain field, better odds than many rural Texas counties, but still worth a site evaluation before you buy¹⁵.

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

McMullen County has no zoning authority, so RV occupancy, tiny-home occupancy and temporary camping on private land are unrestricted by county zoning³. That is a real answer from Texas law, not an absence of a county rule: state law gives McMullen County no power to regulate these uses through zoning³. One statewide rule still applies regardless of zoning: an uninstalled manufactured home may not be occupied for any purpose other than viewing it on a retailer's sales lot, so a manufactured home has to be installed on its site before anyone lives in it¹⁶. If a manufactured home will sit within, partially within, or adjacent to a mapped flood hazard area, it still needs a floodplain development permit from the County Judge's office before placement¹⁷¹³.

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

Check whether your parcel sits in a mapped flood hazard area using the FEMA floodplain maps on the county's website; if it does, file a floodplain development permit with the County Judge's office before you build -- $50 for a single-family residence, $300 for commercial or other activity⁵¹³.
Apply for an OSSF (septic) permit through the county's OSSF program before installing a system, unless your tract qualifies for the state's 10-acre exemption⁷¹⁴.
If you will drill or expand a well, check the McMullen Groundwater Conservation District's rules: a well expected to produce more than 25,000 gallons a day needs a district permit with a $100 application fee, while smaller exempt wells must still be registered⁸.
If your driveway will connect to a state highway or farm-to-market road, submit TxDOT Form 1058 and give TxDOT 24-hour notice before construction begins on the right of way⁹¹⁸.
Because McMullen County has no zoning, there is no county setback, lot-size or building-height review to clear -- confirm only the floodplain, septic and access steps above³.

What to check before you buy land in McMullen County

McMullen County averages 24.7 inches of rain a year and has spent roughly 16.3% of years in severe drought, so confirm well capacity or another water source before closing¹⁹²⁰. About 33.3% of the county's soils are free of severe septic limitations, and all of the county's land sits at 15% slope or less, so terrain rarely limits building here -- soil type and depth to groundwater matter more¹⁵²¹. Federal land covers only 1.5% of the county, so most of McMullen County is private -- confirm mineral and surface ownership separately, since this is active oil and gas country²². The county's effective property tax rate is about 2%, with a median property tax bill of $2,167 a year²³²⁴. McMullen County sits roughly 73 miles from the nearest metro area, with a population density of 0.5 people per square mile, so plan on long drives for services, hardware and emergency response²⁵²⁶.

Watch-outs

McMullen County has no general building permit and no zoning, but skipping the floodplain permit in a mapped flood hazard area is still a real risk -- confirm your parcel's flood status with the County Judge's office before you build¹³².
An uninstalled manufactured home cannot legally be occupied anywhere in Texas except to view it on a retailer's lot, so plan for it to be fully installed on site before anyone moves in¹⁶.
McMullen County's own pages do not state whether an owner-builder exemption, a certificate of occupancy, or a short-term-rental rule exists here -- ask the County Judge's office directly rather than assume either way¹³.

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 McMullen County scores

Seclusion83100% ev.

Self-Sufficiency2396% ev.

Admin Boringness7290% ev.

Durability30100% ev.

Property Autonomy71100% ev.

Carry Cost8094% ev.

Evidence strength: 97%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$109kTypical home

2%Property tax

$1,940Land / acre

24.7"Annual rain

16.3% of yrsSevere drought

77 / yr (+41.3)Mid-century 100°F days

31.2 daysMid-century dry spell

2.19" (+8.5%)Mid-century 1-day rain

1.36×Wildfire change factor

100%Forward climate coverage

state median fallbackInsurance basis

75People within 30 min

2,040,080People within 2 hr

467Radius comparison (15 mi)

0.5People / sq mi

1.5%Federal land

100%Land at 15% slope or less

33.3%Septic soil without severe limits

202,911 acWorkable land screen

23.1%Wooded land

4.2 tonsBiomass / forest ac

71.8°FAvg temp

Answers from the rulebook for McMullen County

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

McMullen County rules

Building permitLimited
Certain development and residential construction activities in McMullen County flood hazard areas, including new structures, additions, relocations, demolitions, replacements, manufactured homes, and related development activity.
- The county's published permit materials identify a floodplain development permit process, but do not establish a general countywide residential building permit requirement.
- The floodplain application lists a $50.00 application fee for a single-family residence and $300.00 for commercial, industrial, or other activity.
- Applicants must submit scaled plans showing locations, dimensions, and elevations of proposed alterations and structures.
- If structures are within, partially within, or adjacent to areas of special flood hazard, certifications under Article 5, Section B of the County's Flood Damage Prevention Ordinance are required from a Texas registered professional engineer, architect, or surveyor.
- Watercourse or natural-drainage alterations or relocations require site plans and a hydrologic and hydraulic study certified by a registered Texas professional engineer.
single-family application fee: 50 USD · commercial, industrial, or other activity application fee: 300 USD
“If you are in a flood zone you will be required to complete a permit application and return it to the County Judge’s office.”
How do I request or apply for permits? ↗Re-checked Sep 11, 2026
Zoning districts · by state lawNo county rule
Unincorporated McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 homesLimited
Placement and related development of manufactured homes in or adjacent to McMullen County areas of special flood hazard.
- A floodplain development permit application is required for the described development process.
- The applicant must submit plans drawn to scale showing the location, dimensions, and elevations of proposed alterations and existing and proposed structures, including placement of manufactured homes.
- If structures are located within, partially, or adjacent to areas of special flood hazard, certifications are required in accordance with Article 5, Section B, Specific Standards, of the County's Flood Damage Prevention Ordinance.
- Certifications must be provided by a Texas Registered Professional Engineer, Architect, or Surveyor.
- The application fee is $50.00 for a single-family residence and $300.00 for commercial, industrial, or other activity.
- The source addresses floodplain development and does not establish a countywide manufactured-home occupancy rule outside those areas.
single-family residence application fee: 50 USD · commercial, industrial, or other activity application fee: 300 USD
“including the placement of manufactured homes, and the location of these improvements or structures in relation to the current effective floodplain or areas special flood hazard.”
Flood Plain Development Permit Application ↗Re-checked Sep 11, 2026
Accessory dwellings · by state lawNo county rule
Unincorporated McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org.
- 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 septicMixed (with conditions)
On-site sewage facility permitting and inspection in McMullen County.
- McMullen County provides the OSSF application and permit materials.
- The local program operates within Texas Health and Safety Code Chapter 366 and 30 TAC Chapter 285.
- Local permitting programs can be more stringent than state minimums.
“Authorization is hereby granted for the Permitting Authority to enter the above described property for the purpose of lot evaluation and inspection of on-site sewage facility and related activities. A permit to operate the facility will be granted following a successful inspection of the system.”
How do I request or apply for permits? – McMullen County ↗Re-checked Sep 11, 2026
Septic inspectionRequired
OSSF systems using the McMullen County OSSF application and permit process.
- The permit to operate is granted only following a successful inspection.
- The permitting authority is authorized to enter the described property for lot evaluation and inspection.
- The county application also includes an on-site final construction inspection field.
“A permit to operate the facility will be granted following a successful inspection of the system.”
McMullen County OSSF Application ↗Re-checked Sep 11, 2026
Well permitLimited
Water wells within the McMullen Groundwater Conservation District, whose documented district extent corresponds to McMullen County.
- A permit is required before drilling or producing a well, or increasing well size or capacity so it could reasonably be expected to produce more than 25,000 gallons per day.
- A permit is not required for drilling exempt wells listed in Rule 3(b), but exempt wells must be registered before drilling.
- Exempt wells are defined as artificial excavations constructed, fitted, or equipped to produce less than 25,000 gallons per day.
- The exemption does not apply when groundwater is used to supply a subdivision for which plat approval is required under Local Government Code Chapter 232.
- Each permit application requires a $100 application fee; a drilling-permit application also requires a $100 deposit.
- The rules state an effective date of September 26, 2012.
exempt-well production threshold: < 25000 gallons per day (Exempt wells must still be registered.) · permit application fee: 100 USD (Permit renewals do not require the application fee unless permit amendments are sought with renewal.) · drilling permit deposit: 100 USD (Deposit is subject to the return conditions and the 180-day deadline stated in Rule 4(b).)
“A permit is required prior to drilling or producing a well, or increasing the size or capacity of a well such that the well could reasonably be expected to produce in excess of 25,000 gallons of water per day. A permit is not required for drilling exempt wells, as listed in Rule 3(b).”
McMullen Groundwater Conservation District Rules ↗Re-checked Sep 11, 2026
Building in a floodplainRequired
Development in a flood zone or area of special flood hazard in McMullen County.
- A permit application must be completed and returned to the County Judge’s office for property in a flood zone.
- The application covers structures and other development activities including clearing, filling, grading, mining, drilling, excavation, subdivision, waterway or drainage alteration, road or bridge construction, and utility work.
- If structures are within, partially within, or adjacent to areas of special flood hazard, certifications under Article 5, Section B of the County Flood Damage Prevention Ordinance are required from a Texas registered professional engineer, architect, or surveyor.
- Watercourse or natural-drainage alterations require a hydrologic and hydraulic study certified by a registered Texas professional engineer.
- Applicants must obtain other required federal, state, or local permits, including potential Section 404 approval.
single-family residence application fee: 50 USD · commercial, industrial, or other activity application fee: 300 USD
“If you are in a flood zone you will be required to complete a permit application and return it to the County Judge’s office.”
Welcome to McMullen County ↗Re-checked Sep 11, 2026
Permit feesPublished (with conditions)
McMullen County floodplain development permit applications.
- The published fee is $50.00 for a single-family residence.
- The published fee is $300.00 for commercial, industrial, or other activity.
- Payment must be made by cash, check, or money order payable to McMullen County.
single-family residence application fee: 50 USD · commercial, industrial, or other activity application fee: 300 USD
“CASH/CHECK/MONEY ORDER MADE OUT TO "McMULLEN COUNTY": $50.00 for Single-Family residence $300.00 for Commercial, Industrial, or other activity”
Flood Plain Development Permit Application ↗Re-checked Sep 11, 2026
County-wide zoningAbsent
The county regulates only subdivisions and floodplain development, not land-use zoning; Texas counties generally have no zoning authority in unincorporated areas.
McMullen County - Permits ↗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
Septic permitLimited
OSSF construction, installation, alteration, extension, repair, or operation in McMullen County, subject to the Texas OSSF program and local permitting authority.
- A permit is required to construct, install, alter, extend, or repair an OSSF.
- The 10-acre exemption requires a TCEQ-licensed Site Evaluator or Professional Engineer site evaluation; a single-family dwelling on a tract of at least 10 acres; no nuisance or groundwater pollution; all OSSF parts at least 100 feet from the property line; effluent disposal on the property; and the single-family dwelling must be the only dwelling on the tract.
- Emergency repairs listed by TCEQ are exempt from permitting but must be reported in writing to the permitting authority within 72 hours after repairs begin.
- Grandfathered systems may also not need a permit, subject to the conditions stated by TCEQ.
- Always check with the local permitting authority; local programs may be more stringent than state minimums.
10-acre exemption tract size: >= 10 acres (All other TCEQ conditions must also be met.) · minimum distance from property line: >= 100 feet (Applies to all parts of an OSSF qualifying for the 10-acre exemption.) · emergency-repair reporting deadline: <= 72 hours (Report in writing after repairs have begun.)
“A permit is required to construct, install, alter, extend, or repair an OSSF. Always check with your local permitting authority. Local permitting programs can be more stringent than State minimums.”
Getting a Permit for an OSSF - Such as a Septic System ↗Re-checked Sep 11, 2026
One more reviewed finding on this topic
- Required — Construction, installation, alteration, extension, or repair of an OSSF in Texas
  “A permit is required to construct, install, alter, extend, or repair an OSSF. [...] An OSSF may be exempt from permitting if it complies with all other requirements, including planning, construction, and installation standards of 30 TAC 285 AND meets the “10 acre rule”:”
  Getting a Permit for an OSSF - Such as a Septic System ↗Re-checked Sep 12, 2026
Off-grid sanitationLimited
On-site or off-grid sewage disposal through an OSSF in McMullen County.
- An OSSF generally requires a permit and approved planning materials.
- A qualifying single-family residence on a tract of at least 10 acres may be exempt only if all TCEQ 10-acre-rule conditions are met.
- Emergency repairs may be exempt from permitting only if reported in writing within 72 hours after repairs begin.
- Even where permitting is exempt, applicable planning, construction, installation, nuisance, groundwater-protection, and local-authority requirements continue to apply.
minimum tract size for 10-acre exemption: >= 10 acres (Single-family residence and all other TCEQ conditions required.) · minimum OSSF distance from property line: >= 100 feet (Required for the 10-acre exemption.)
“A permit and approved plan are required to construct, alter, repair, extend, and operate an OSSF.”
Getting a Permit for an OSSF - Such as a Septic System ↗Re-checked Sep 11, 2026
Driveway accessRequired
New or modified access driveways connecting property to a Texas state highway right of way.
- A local public agency may receive access driveway permitting authority for state highways, but TxDOT approval remains required for drainage impacts on the state highway system before local approval.
- No access driveway is permitted within a flared or widened right-of-way section at an intersection of a state highway with another highway, road, or street.
- All entrances and exits, including radii, must be confined within the permittee's property frontage.
- One-way 45-to-90-degree driveways are permitted for connections to one-way frontage roads or lane-divided highways; otherwise the driveway angle must be 75 to 90 degrees.
- ADAAG and Texas Accessibility Standards apply.
private residential driveway maximum width: <= 24 feet (Except as increased by permissible radii.) · driveway-to-pavement radius: >= 15 feet
“A driveway must be constructed in accordance with a fully executed driveway permit”
Section 4: Driveway Permits, Design, and Materials ↗Re-checked Sep 12, 2026
One more reviewed finding on this topic
- Limited — New or modified driveway access from a property in McMullen County onto a state highway or FM roadway right-of-way.
  “If your driveway will be coming off of a Highway or FM you will need to contact TX Dot at the below number for a permit. Once the permit is issued you will be given an address.”
  911 Address ↗Re-checked Sep 11, 2026
Permit processPublished (with conditions)
Constructing a new driveway or revising an existing driveway on the right of way of a Texas state highway.
- The applicant should contact the local District TxDOT office.
- The applicant must submit Form 1058, Permit to Construct Access Driveway Facilities on Highway Right of Way.
- The application must be for the bona fide purpose of securing or changing access to the owner's property, not parking or servicing vehicles on state highway rights of way.
- No construction may begin on the right of way until a fully executed driveway permit is received and the applicant gives TxDOT 24-hour notification.
- The driveway must comply with the executed permit and applicable regulations; TxDOT inspection must find construction satisfactory.
- Where a local public agency has permitting authority, drainage impacts on the state highway system still require TxDOT approval before local approval.
- Driveway geometrics, utilities, environmental requirements, wetlands considerations, ADAAG, TAS, and other applicable state and federal laws must be considered.
required form: Form 1058, Permit to Construct Access Driveway Facilities on Highway Right of Way · advance notification: 24 hours (Notification to TxDOT is required before construction on the right of way.) · private residential driveway maximum width: <= 24 feet (Except as increased by permissible radii.) · minimum driveway radius to highway pavement: >= 15 feet
“The applicant shall complete and submit to TxDOT a Form 1058”
Section 4: Driveway Permits, Design, and Materials ↗Re-checked Sep 12, 2026
Campground & park staysLimited
Temporary camping in a public place in Texas, including McMullen County.
- The prohibition applies when a person intentionally or knowingly camps in a public place without the effective consent of the officer or agency having the legal duty or authority to manage that public place.
- The statute defines camping as residing temporarily in a place with shelter.
- The source does not establish a rule for camping on private land.
“camps in a public place without the effective consent of the officer or agency having the legal duty or authority to manage the public place.”
Texas Penal Code Chapter 48, Section 48.05 ↗Re-checked Sep 11, 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.

Owner-builder exemption — Owner-builders constructing or improving residential structures in McMullen County.
Inspections — Building inspections for residential or other structures in McMullen County.
Certificate of occupancy — Certificates of occupancy for buildings in McMullen County.
Local zoning — Local zoning within McMullen County, including incorporated municipalities and any other local jurisdictions.
Mandatory utility hookup — Requirements to connect to public water or sewer systems, or permission to use no utility connection, in McMullen County.

2 more unanswered

Agricultural exemption
Short-term rentals

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 McMullen County, Texas

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

McMullen County scores 51/100 on the Bolthole Index, a solid county profile. Its strengths: sparse surroundings — about 75 people within a 30-minute drive and manageable long-term carry cost. Watch-outs: thin water margin (24.7″/yr rainfall) and elevated mid-century heat, water, rain, or wildfire exposure.

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

McMullen County requires a building permit only in limited cases (such as floodplains or specific zones), and it has no county-wide zoning. Onsite septic is permitted by McMullen County (OSSF authorized agent, per TCEQ Ch. 366). 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 McMullen County?

Living in an RV on your own land in McMullen County is allowed: Unincorporated McMullen County: no county rule sets this, because Texas law gives zoning power only to certain counties, and McMullen County has no zoning ordinance. The county legal census found no county zoning ordinance, citing mcmullencounty.org. 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 McMullen County, Texas?

Land in McMullen County runs about $1,940 per acre, based on the latest county data.

What is the water situation in McMullen County?

McMullen County gets about 24.7" of rain a year, with severe drought in roughly 16.3% of years.

How remote is McMullen County?

A representative private-land location has about 75 people within a 30-minute drive and 2,040,080 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 McMullen County, Texas

At a glance

Who to call

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

Who handles floodplain and permit questions in McMullen County?

Does McMullen County have zoning?

How do septic permits work in McMullen County?

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

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

What to check before you buy land in McMullen County

Watch-outs

Sources

McMullen County in Texas

How McMullen County scores

Find land. Bring the promising ones back.

Parcel due diligence

Answers from the rulebook for McMullen County

McMullen County rules

Texas rules that apply here

Still unanswered

Living off-grid in McMullen County, Texas

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

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

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

How much does land cost in McMullen County, Texas?

What is the water situation in McMullen County?

How remote is McMullen County?

How McMullen compares in Texas