Caldwell County, TX Building Permits, Zoning & Septic Rules

Unincorporated Caldwell County, Texas requires a Residential Construction Permit before you build or install a residential structure, including a manufactured home or an RV used as housing¹². The county has no countywide zoning, but municipal or special-purpose zoning can still affect some parcels³⁴. Caldwell County Sanitation/Development Services handles residential construction and septic permits⁵⁶.

At a glance

Building permit: Residential Construction Permit required; published fee is $225 and the permit is valid for 2 years¹⁷²
Zoning: No countywide zoning in unincorporated areas; municipal and special-purpose rules can still apply³⁴
Septic permits: County permit, site evaluation and installation inspection required⁸⁹
RV / tiny home living: No county zoning restriction, but an RV used as housing falls within the residential permit definition¹⁰²
Manufactured home: Residential permit required; mobile homes must be anchored and have a closed-in foundation²
Owner-builder exemption: We could not confirm one; ask Sanitation/Development Services¹¹⁵
Water: Permit application may use utility proof, a private-well log or a certified rainwater system¹²
Driveway access: County right-of-way work needs a county permit; state-highway access follows TxDOT's process¹³¹⁴

Who to call

Building permits

Caldwell County Sanitation/Development Services

Residential and commercial site construction permits, subdivision and development review, floodplain management, platting, and code enforcement for unincorporated Caldwell County.

(512) 398-1803

1700 FM 2720, Lockhart, TX 78644

Septic permits

Caldwell County Sanitation/Development Services

OSSF (septic) permits, inspections and complaints for unincorporated Caldwell County; application forms include a dedicated Application for Septic Permit.

(512) 398-1803

1700 FM 2720, Lockhart, TX 78644

Codes & inspections

Caldwell County Development Ordinance (Sec. 4.4, Residential Construction Permit)

The county's own written ordinance defining what requires a Residential Construction Permit, what's exempt, what a residential structure is (including manufactured homes and RVs used as housing), and what an application must include.

Contact details are copied from each office’s official page and were checked against it on September 29, 2026.

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

Unincorporated Caldwell County, Texas requires a Residential Construction Permit for a new residential structure, an addition that increases bathroom or bedroom count, or major rebuilding after fire or flood¹². The published residential permit fee is $225, and starting work before approval doubles the applicable fee⁷. Caldwell County exempts enclosing a staircase or porch, a carport for fewer than 10 cars, a deck, roof replacement, exterior-facade remodeling and sidewalk construction². The permit remains valid for 2 years or until construction is complete². An application needs land and ownership records, current tax certificates, and a site sketch that identifies the proposed work, access, property lines, floodplain, easements, wells and septic components².

Who is the Caldwell County building department, and how do you reach them?

Caldwell County Sanitation/Development Services handles residential and commercial site construction permits, septic permits and inspections, subdivision and development review, floodplain management, platting and code enforcement⁵. The office is at 1700 FM 2720, Lockhart, TX 78644, and its phone number is (512) 398-1803⁵. Call for an appointment before submitting a project⁵. Caldwell County publishes applications for residential construction, septic, subdivision, floodplain, construction and variance requests, along with its development fee schedule¹⁵. A parcel split or subdivision adds another layer: Commissioners Court approval is required before a subdivision or resubdivision plat can be recorded, and projects in a municipality's ETJ may also require submission to that municipality¹⁶.

Does Caldwell County have zoning?

Unincorporated Caldwell County has no countywide zoning or general county land-use zoning power³. At the county level, that means no zoning rule sets minimum dwelling size, minimum lot size, setbacks, lot coverage or building height¹⁰. Parcel-specific rules can still come from a city or a special-purpose district; airport zoning administered by the City of San Marcos may affect development within its hazard area in Caldwell County⁴. No countywide zoning does not mean no permits: residential construction, septic, floodplain work, subdivisions and county-road access remain regulated through other county processes¹⁸¹⁶¹³. Before relying on the countywide answer, ask Sanitation/Development Services whether the parcel lies in a municipal ETJ, airport hazard area or another special jurisdiction⁴⁵.

How do septic permits work in Caldwell County?

Caldwell County Sanitation/Development Services issues OSSF permits and requires a site evaluation to determine soil suitability and the system type⁸⁶. The regular single-family conventional-system fee is $400, the engineered-system fee is $450, and an approved permit is valid for 1 year and is non-refundable⁸. A complete design receives a 5-day review if no design changes are needed¹⁵. Type 1a soil, floodplain sites and subdivisions restricted to engineered systems require design by an engineer or registered sanitarian⁸. Installation requires advance notice for an inspection and an installer or installer apprentice must be present; successful inspection leads to the permit to operate⁹. Texas's 10-acre exemption may apply only when every state condition is met, including one home, a qualifying site evaluation and at least 100 feet between every system component and a property line¹⁷.

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

Caldwell County has no county zoning restriction on RV occupancy, temporary camping, tiny-home occupancy or manufactured-home occupancy in unincorporated areas¹⁰. A separate permit rule still matters: the Development Ordinance defines a residential structure to include a manufactured home or recreational vehicle used to house a family, so an RV used as housing falls within the Residential Construction Permit framework². A tiny home used as a dwelling also fits the county's general permit requirement for construction or installation of a residential structure¹. Mobile homes must be tied down or anchored and have a closed-in foundation². Ask Sanitation/Development Services how the office will classify the exact unit and setup before delivery, especially if the plan is temporary occupancy during construction⁵. Municipal or airport-area rules may differ on affected parcels⁴.

Building a home in Caldwell County: the steps, in order

Call Caldwell County Sanitation/Development Services at (512) 398-1803 to identify the residential, septic, floodplain, subdivision and access approvals for the parcel⁵.
Confirm whether municipal, ETJ or airport-area rules add another review⁴¹⁶.
Assemble the property description, ownership record, current tax certificates and site sketch required for the residential application².
Document potable water with a utility receipt or bill, a private-well driller's log, or an engineered or certified rainwater system¹².
Complete the septic site evaluation and secure the county OSSF permit before installation⁸.
Apply for county driveway approval when work touches a county right-of-way; a new or materially changed driveway may be reviewed with the site permit¹³.
Use TxDOT's Form 1058 instead when access connects to a state highway¹⁴.
Obtain the residential permit before work begins to avoid doubled fees⁷.

What to check before you buy land in Caldwell County

Ask Sanitation/Development Services whether the parcel is in or within 300 feet of a floodplain, because that changes floor-elevation and permit documentation requirements². Only 3.8% of Caldwell County soils are rated without severe limitations for a conventional drain field, so get the septic site evaluation before fixing the house site or purchase budget¹⁸⁸. Confirm access too: county right-of-way work needs a county permit, while a state-highway connection follows TxDOT's separate process¹³¹⁴. If land will be divided, verify plat approval and whether ETJ review applies before closing¹⁶. Finally, identify the potable-water plan; the residential application accepts utility documentation, a private-well driller's log, or an engineered or certified rainwater system, but we could not confirm the separate water-well permitting authority¹².

Watch-outs

Caldwell County's ordinance does not state whether an owner-builder exemption applies to the Residential Construction Permit; ask Sanitation/Development Services directly before you plan to self-build¹¹⁵.
Countywide zoning is absent, but municipal and special-purpose zoning can still affect a parcel, including San Marcos airport zoning in its hazard area³⁴.
A septic permit in the 100-year floodplain will not issue until the development permit for the served structure is approved⁸.

Sources

Written September 29, 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 Caldwell County scores

Seclusion38100% ev.

Self-Sufficiency5096% ev.

Admin Boringness5990% ev.

Durability43100% ev.

Property Autonomy71100% ev.

Carry Cost73100% 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 →

$288kTypical home

1.3%Property tax

$4,814Land / acre

35.5"Annual rain

24.6% of yrsSevere drought

39.6 / yr (+27.9)Mid-century 100°F days

25.7 daysMid-century dry spell

2.29" (+7.1%)Mid-century 1-day rain

1.43×Wildfire change factor

100%Forward climate coverage

$1,688Home insurance / yr

0.6% / yrInsurance growth

0%Nonrenewal rate

county median (2+ published ZIPs)Insurance basis

19,669People within 30 min

7,357,981People within 2 hr

77,550Radius comparison (15 mi)

91.6People / sq mi

0%Federal land

100%Land at 15% slope or less

3.8%Septic soil without severe limits

13,296 acWorkable land screen

24.6%Wooded land

14.9 tonsBiomass / forest ac

69°FAvg temp

Answers from the rulebook for Caldwell County

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

Caldwell County rules

County-wide zoningAbsent
County zoning or land-use regulatory powers in unincorporated Caldwell County.
- Municipal zoning and special-purpose zoning may still apply to particular areas, including airport-related zoning administered by the City of San Marcos.
“The resolution acknowledged citizen concerns about data centers that include impacts on quality of life, public health and the environment and detailed the limitations of county government to regulate development, reminding citizens that counties do not have zoning or land-use regulatory powers like cities do.”
Commissioners approve resolution regarding data centers ↗Re-checked Sep 26, 2026
Local zoningVaries (with conditions)
Aggregate of municipal and special-purpose zoning affecting land in Caldwell County; the county itself does not administer each local ordinance.
- Caldwell County states that counties do not have zoning or land-use regulatory powers like cities do.
- The City of San Marcos airport zoning ordinance may apply to some development in Caldwell County within the identified hazard zone.
“The City has passed an airport zoning ordinance and incorporated that into the City Code in Article 3, Section 10. This ordinance regulates, as allowed by state law, development height to prevent hazards to the City's airport and land use compatibility in the neighborhood of the airport.”
Commissioners approve resolution regarding data centers ↗Re-checked Sep 26, 2026
Zoning districts · by state lawNo county rule
Unincorporated Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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 Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning.
- 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
Septic permitRequired
Construction of an on-site sewage facility in Caldwell County.
- A site evaluation determines soil type and site suitability and determines the system type that can be installed.
- If the site is in Type 1a soil, in the floodplain, or in a subdivision restricted to engineered systems, an engineer or registered sanitarian is required to design the system.
- The approved permit is good for one year and is non-refundable.
- A permit to construct an OSSF in the 100-year floodplain will not be issued until a development permit for the structure using the facility has been approved.
regular conventional single-family septic permit fee: 400 USD · engineered single-family septic permit fee: 450 USD · permit validity: 1 year (Approved permit is non-refundable.)
“After this office receives the following items, a five day review (if no changes to the design) of the submittal is necessary before permit is issued.”
Caldwell County Septic Application ↗Re-checked Sep 26, 2026
Septic inspectionRequired
Installation and operation approval of an on-site sewage facility in Caldwell County.
- Twenty-four-hour notice is required before inspection.
- An installer or installer apprentice must be on site during construction and inspection.
- A permit to operate is granted following successful inspection showing compliance with TCEQ OSSF construction standards.
“A twenty-four hour notice must be given to this office (512-398-1803) requesting an inspection. An installer or an installer apprentice shall be on-site during construction and inspection.”
Caldwell County Septic Application ↗Re-checked Sep 26, 2026
Mandatory utility hookupConditional
Potable-water arrangements for residential construction permit applications.
- Proof of potable water service may be shown by a paid impact or meter fee receipt, water bill, private water-well drillers log, or engineered or certified rainwater collection system.
- The source does not establish a universal requirement to connect to a public water or sewer utility.
“Proof of potable water service in the form of 1) receipt for paid impact/ meter fees from the applicable water supplier, 2) water bill, OR 3) copy of drillers log for private water well. 4) an engineered or certified rainwater collection system.”
Caldwell County Development Ordinance ↗Re-checked Sep 26, 2026
Subdividing landRegulated (with conditions)
Subdivision and resubdivision of land in unincorporated Caldwell County, including plats, streets, drainage, utilities, and related construction.
- A subdivision or resubdivision plat must be approved by Commissioners Court before recording.
- Construction drawings and specifications must be submitted and a construction permit issued before land clearing and construction for subdivision or site construction.
- Applications in a municipality's ETJ may require concurrent submission to the municipality or other governmental entity under an interlocal agreement or applicable jurisdiction.
“No party shall file for record or have recorded in the official records of the County Clerk's office any plat of a subdivision or re-subdivision without first securing approval thereto by the Commissioners Court, in lawful, open session.”
Caldwell County Development Ordinance ↗Re-checked Sep 26, 2026
Driveway accessLimited
New driveways, improvements to existing driveways, or site-use changes that raise questions about driveway adequacy; and activity in county rights-of-way.
- A driveway permit application must accompany the site construction permit in the stated circumstances.
- Work in the county right-of-way, including construction, expansion, or rehabilitation of driveways, requires a Work in the Public Right-of-Way Permit.
- Applications are reviewed concurrently.
“If the site construction includes a new driveway or improvement of an existing driveway, or if it alters the intensity of the site use so as to bring into question the adequacy of the existing driveway under this ordinance, the site construction permit shall be accompanied by a driveway permit application. Applications for the site construction and driveway permits will be reviewed concurrently.”
Caldwell County Development Ordinance ↗Re-checked Sep 26, 2026
Permit feesPublished (with conditions)
Caldwell County subdivision, development, residential construction, site construction, driveway, utility-right-of-way, and floodplain permit fees.
- Fees are doubled for development or construction commenced before obtaining the appropriate approval.
- The fee schedule lists separate fees by permit type and construction-cost range.
residential construction permit: 225 USD · driveway work in right-of-way permit: 50 USD · floodplain permit or revision: 750 USD (Plus reimbursement of consultant cost.) · subdivision construction: 1.5 percent of cost of streets and drainage
“Work in R.O.W Permit (Driveway) $50 [...] Residential Construction Permit $225 [...] Floodplain Permits/ Revisions $750 plus reimbursement of consultant cost”
Caldwell County Subdivision and Development Fee Schedule ↗Re-checked Sep 26, 2026
Permit processPublished (with conditions)
County development, construction, subdivision, floodplain, residential construction, and septic permit processes.
- The county publishes applications and forms for septic, residential construction, subdivision, floodplain, construction, variance, and related permits.
- Residential construction applications require recorded ownership, tax certificates, site information, potable-water proof, floodplain information when applicable, and an approved OSSF permit when applicable.
- Septic submittals receive a five-day review if there are no design changes.
septic review time: 5 days (If no changes to the design.)
“Application for Septic Permit Application for Residential Construction Permit Mass Gathering Permit Resubmittal Form Development Fee Schedule Development Agreement Application Floodplain Application Construction Application Variance Application Traffic Impact Analysis Application”
Sanitation/Development Services ↗Re-checked Sep 26, 2026
Building permitRequired
Unusually for Texas, Caldwell County's Development Ordinance (Sec. 4.4) requires a Residential Construction Permit for the construction or installation of any residential structure in the unincorporated county (minor work like decks, carports, roof replacement is exempt).
Caldwell County Development Ordinance ↗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
Who permits septicMixed
On-site sewage facilities, including septic systems, throughout Texas
- In most areas, local governments act as TCEQ-authorized agents and administer the OSSF program.
- The TCEQ regional office is the permitting authority where a local jurisdiction has not been authorized.
- Local permitting programs may be more stringent than state minimums.
“TCEQ is not often the OSSF permitting authority. [...] The TCEQ regional office will be the permitting authority in locations where a local jurisdiction has not been authorized.”
Getting a Permit for an OSSF - Such as a Septic System ↗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.

Owner-builder exemption — Owner-builder exemptions from Caldwell County residential construction permitting.
Certificate of occupancy — Certificate-of-occupancy requirements for buildings in unincorporated Caldwell County.
Off-grid sanitation — Off-grid sanitation systems in unincorporated Caldwell County.
Well permit — Private and commercial water-well permitting in Caldwell County.
Short-term rentals — Short-term rental use in Caldwell County.

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 Caldwell County, Texas

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

Caldwell County scores 58/100 on the Bolthole Index, a solid county profile. Its strengths: manageable long-term carry cost and a stronger property-autonomy legal backdrop. Watch-outs: sparse surroundings — about 19,669 people within a 30-minute drive.

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

Caldwell County generally requires a residential building permit, and it has no county-wide zoning. Onsite septic is permitted by Caldwell County Sanitation / Development Services (TCEQ authorized agent). 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 Caldwell County?

Living in an RV on your own land in Caldwell County is allowed: Unincorporated Caldwell County: no county rule sets this, because Texas law gives zoning power only to certain counties, and Caldwell County has no zoning ordinance. Caldwell County's own reviewed answer confirms it has no county-wide zoning. 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 Caldwell County, Texas?

Land in Caldwell County runs about $4,814 per acre, based on the latest county data.

What is the water situation in Caldwell County?

Caldwell County gets about 35.5" of rain a year, with severe drought in roughly 24.6% of years.

How remote is Caldwell County?

A representative private-land location has about 19,669 people within a 30-minute drive and 7,357,981 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 Caldwell County, Texas

At a glance

Who to call

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

Who is the Caldwell County building department, and how do you reach them?

Does Caldwell County have zoning?

How do septic permits work in Caldwell County?

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

Building a home in Caldwell County: the steps, in order

What to check before you buy land in Caldwell County

Watch-outs

Sources

Caldwell County in Texas

How Caldwell County scores

Find land. Bring the promising ones back.

Parcel due diligence

Answers from the rulebook for Caldwell County

Caldwell County rules

Texas rules that apply here

Still unanswered

Living off-grid in Caldwell County, Texas

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

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

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

How much does land cost in Caldwell County, Texas?

What is the water situation in Caldwell County?

How remote is Caldwell County?

How Caldwell compares in Texas