On this page 6
§ 02
When a permit is required
Permit triggers and exempt work for Trinity County
No public countywide general building permit program was found for ordinary building construction in unincorporated Trinity County. Published county permit and approval controls include: OSSF and septic permits, subdivision and plat approval under county subdivision regulations, heavy-haul permits for county roads, and 911 address assignment and GIS coordination.
OSSF work may qualify for state-law exemptions when statutory conditions are met, such as the Ten Acre Exemption affidavit
- Exempt OSSF work may qualify for state-law exemptions when statutory conditions are met, such as the Ten Acre Exemption affidavit
Note: No public county exempt-work list for general building work because no public countywide general building-permit program was found. For heavy-haul activity, the county publishes a Heavy Haul Permit form through the Commissioners forms page rather than an exemption list.
Required documents
- For OSSF: application, site evaluation report, system design, and for aerobic systems the affidavit to the public and maintenance agreement
- For subdivision: plans and plat per subdivision regulations
- For heavy-haul: county heavy-haul permit request
- Building code
- No public countywide building-code adoption or general county building-code enforcement program was found.
- Owner-builder
- For OSSF, any person other than the homeowner who installs a system must hold the required state installer license.
- Contractor requirements
- For OSSF: designs must come from a Texas licensed professional engineer or registered sanitarian; site evaluations must be performed by a licensed site evaluator; non-owner installers must be licensed by the State of Texas as Installer 1 or Installer 2 depending on the system.
§ 03
Application process
Application → plan check → issuance → inspection → final
- 01 Determine whether the project falls into one of the county's published approval programs (OSSF, subdivision, heavy-haul, or addressing).
- 02 For OSSF and septic work, contact the County Judge's Office to obtain the permit application and packet.
- 03 Obtain a site evaluation from a licensed site evaluator and a septic design from a Texas licensed professional engineer or registered sanitarian, then submit those items with the permit application.
- 04 If the system uses secondary treatment (aerobic), provide the required affidavit to the public, maintenance agreement, and recorded documents before final operation approval.
- 05 Wait for county review. If compliant, the county issues an Authorization to Construct.
- 06 Request inspections before any lines or tanks are covered and at least two days before installation unless waived by the assigned designated representative.
- 07 For subdivision projects, follow county subdivision regulations and pay listed development and engineering-review fees.
- 08 For heavy-haul use on county roads, submit the permit through the Commissioners forms page before hauling begins.
§ 04
Fee schedule
Trinity County building permit fees
Fee type
Amount
01
Minimum permit fee
$5
02
Plan check fee
Minor subdivision $3,000, rural subdivision with road $5,000, major subdivision $6,000, RV park $5,000, or amount set in consultation with engineer for exceptional situations
03
Permit fee formula
Flat fees. OSSF: Residential standard $325, residential multi-family $325, commercial/business $450, each additional RV at business sites $50, maintenance reports and contracts $5, affidavit aerobic or 10 acre exemption $25. Subdivision: major $750 initial and $750 approved, rural subdivision with road $750 initial and $750 approved, minor subdivision $500 initial and $500 approved, replat $250 plus posting/publishing initially and $250 on approval, recording of approved plat $250.
Fees change periodically. Confirm at the official fee schedule ↗ before budgeting.
§ 05
Required inspections
Scheduling and sequence
- Scheduling deadline
- For OSSF, inspections must be requested before any lines or tanks are covered and should be requested at least two days prior to installation unless the assigned designated representative waives that lead time.
Typical sequence: For OSSF: site evaluation, system design, permit application, county review, Authorization to Construct, installation, pre-cover inspection, and final approval. For aerobic systems, final permit release is held pending the recorded affidavit and maintenance documentation.
§ 06
Frequently asked
Common questions about unincorporated Trinity County permits
01 Do I need a building permit in unincorporated Trinity County, TX? ▸
No public countywide general building permit program was found for ordinary building construction in unincorporated Trinity County. Published county permit and approval controls include: OSSF and septic permits, subdivision and plat approval under county subdivision regulations, heavy-haul permits for county roads, and 911 address assignment and GIS coordination.
02 How much does a building permit cost in unincorporated Trinity County, TX? ▸
Building permit fees in unincorporated Trinity County, TX are set by the local building department and vary by project type and valuation. The minimum permit fee is $5. Fees are calculated as: Flat fees. OSSF: Residential standard $325, residential multi-family $325, commercial/business $450, each additional RV at business sites $50, maintenance reports and contracts $5, affidavit aerobic or 10 acre exemption $25. Subdivision: major $750 initial and $750 approved, rural subdivision with road $750 initial and $750 approved, minor subdivision $500 initial and $500 approved, replat $250 plus posting/publishing initially and $250 on approval, recording of approved plat $250.. Plan check fee: Minor subdivision $3,000, rural subdivision with road $5,000, major subdivision $6,000, RV park $5,000, or amount set in consultation with engineer for exceptional situations.
03 How do I apply for a building permit in unincorporated Trinity County, TX? ▸
To apply for a building permit in unincorporated Trinity County, TX, follow these steps: 1. Determine whether the project falls into one of the county's published approval programs (OSSF, subdivision, heavy-haul, or addressing). 2. For OSSF and septic work, contact the County Judge's Office to obtain the permit application and packet. 3. Obtain a site evaluation from a licensed site evaluator and a septic design from a Texas licensed professional engineer or registered sanitarian, then submit those items with the permit application. 4. If the system uses secondary treatment (aerobic), provide the required affidavit to the public, maintenance agreement, and recorded documents before final operation approval. 5. Wait for county review. If compliant, the county issues an Authorization to Construct. 6. Request inspections before any lines or tanks are covered and at least two days before installation unless waived by the assigned designated representative. 7. For subdivision projects, follow county subdivision regulations and pay listed development and engineering-review fees. 8. For heavy-haul use on county roads, submit the permit through the Commissioners forms page before hauling begins.
04 What work is exempt from building permits in unincorporated Trinity County, TX? ▸
Not all construction work requires a permit in unincorporated Trinity County, TX. The following work is generally exempt: OSSF work may qualify for state-law exemptions when statutory conditions are met, such as the Ten Acre Exemption affidavit. Note: No public county exempt-work list for general building work because no public countywide general building-permit program was found. For heavy-haul activity, the county publishes a Heavy Haul Permit form through the Commissioners forms page rather than an exemption list. When in doubt, confirm with the local building department before starting work.
last verified April 2026
source Trinity County (County Judge's Office, Commissioners Court, Commissioners' Office, 911 Addressing and GIS Mapping) ↗
entry id permits/texas/trinity/unincorporated
Educational reference. Permit rules and fees change — confirm current requirements directly with Trinity County (County Judge's Office, Commissioners Court, Commissioners' Office, 911 Addressing and GIS Mapping) before applying. Jaspector is not legal advice.