Knox County, TX - 2026 Building Permit Guide

Permit Authority

Unincorporated Knox County only, not Benjamin, Goree, Knox City, or Munday.

Department

Knox County / Texas Commission on Environmental Quality Region 3 OSSF Program

Address

Knox County Courthouse, 100 W Cedar St, Benjamin, TX 79505; TCEQ Region 3 OSSF: 1977 Industrial Blvd, Abilene, TX 79602-7833

Phone

Knox County main line: (940) 459-2191; TCEQ Region 3 OSSF: 325-698-9674

Email

nathan.helms@tceq.texas.gov

Website

https://www.knoxcountytexas.org/

Online Permit Portal

Application Process

1. Verify the parcel is in unincorporated Knox County and not inside any incorporated city.
2. For septic work, use TCEQ OARS to confirm the permitting authority. Knox County returns REGION 03 - ABILENE as the authorized agent.
3. Arrange a site evaluation by a licensed site evaluator or professional engineer and gather the planning materials required for the proposed OSSF.
4. Complete TCEQ-0235 and assemble the required supporting materials, including owner information, site address, legal description support, water source data, site evaluation, and design or planning materials.
5. Submit the package and fee to TCEQ Region 3 in Abilene.
6. TCEQ must approve or deny the planning materials and permit application within 30 days of receipt.
7. Do not begin construction before authorization to construct is issued.
8. The installer must notify the permitting authority at least five working days before the system is ready for inspection.
9. The permitting authority conducts the construction inspection and issues deficiency notice if needed.

Typical processing time: TCEQ states OSSF permit applications must be approved or denied within 30 days of receipt

Source: Knox County / Texas Commission on Environmental Quality Region 3 OSSF Program

General Requirements

A permit and approved plan are required to construct, alter, repair, extend, or operate an OSSF in unincorporated Knox County.

Required Documents

• Owner information
• Mailing address
• 911 site address
• Legal description support
• Water source information
• Site evaluator and installer information
• Planning materials as applicable

Permit validity

Authorization to construct is valid for one calendar year from issuance. If the installer does not request a construction inspection within one year, the authorization expires and a new application and fee are required.

Building code

No public Knox County building code adoption or county building code enforcement page was found in the reviewed county materials.

Owner-builder

A homeowner may install an OSSF if it is for a single-family dwelling the homeowner owns on property the homeowner owns, no part of the property is developed for sale or lease, and all permitting, construction, and maintenance requirements are met.

Contractor requirements

OSSF work must be performed by a licensed installer or directly by a qualifying homeowner under the homeowner exception.

Fees

Permit fee formula

TCEQ states permit fees are paid to the authorized agent or the commission, whichever performs the permitting function.

Payment note

Confirm the current OSSF fee amount and payment method directly with TCEQ Region 3 before submission because no Knox County-specific fee sheet was found.

Work That Does NOT Require a Permit

• The 10 acre rule: a permit may be exempt if all stated conditions are met, including the required site evaluation, single-family residential use on a tract of 10 acres or more, and the stated setback and on-site disposal conditions
• Emergency OSSF repairs are not required to obtain a permit, but the repairs must be reported to the permitting authority in writing within 72 hours after repairs begin

Important: For OSSF only. No public county exempt-work list for general building work was found.

Inspections

How to Schedule

• TCEQ Region 3 (phone)

Scheduling deadline

The installer must notify the permitting authority at least five working days before the date the system will be ready for inspection.

Inspection hours

Monday through Friday, 8:00 a.m. to 5:00 p.m.

Typical inspection sequence: OSSF authorization to construct, installation, notice to TCEQ Region 3, construction inspection, correction of deficiencies if needed, then approval before use.

Additional Resources

• Building code: No public Knox County building code adoption or county building code enforcement page was found in the reviewed county materials.
• Verify contractor license: CSLB License Lookup
• Owner-builder rules: View rules
• Knox County Official Website
• Knox County Directory
• TCEQ OARS County Authority Search
• TCEQ Region 3 Contacts
• License lookup guide: Texas Contractor License Requirements
• Contract template: Texas Homeowner-Contractor Agreement
• Texas hub: Texas Contractor License & Permit Hub

Frequently Asked Questions

Knox County Building Permit FAQ

Do I need a building permit in unincorporated Knox County, TX?

A permit and approved plan are required to construct, alter, repair, extend, or operate an OSSF in unincorporated Knox County.

How much does a building permit cost in unincorporated Knox County, TX?

Fees are calculated as: TCEQ states permit fees are paid to the authorized agent or the commission, whichever performs the permitting function..

How do I apply for a building permit in unincorporated Knox County, TX?

1. Verify the parcel is in unincorporated Knox County and not inside any incorporated city. 2. For septic work, use TCEQ OARS to confirm the permitting authority. Knox County returns REGION 03 - ABILENE as the authorized agent. 3. Arrange a site evaluation by a licensed site evaluator or professional engineer and gather the planning materials required for the proposed OSSF. 4. Complete TCEQ-0235 and assemble the required supporting materials, including owner information, site address, legal description support, water source data, site evaluation, and design or planning materials. 5. Submit the package and fee to TCEQ Region 3 in Abilene. 6. TCEQ must approve or deny the planning materials and permit application within 30 days of receipt. 7. Do not begin construction before authorization to construct is issued. 8. The installer must notify the permitting authority at least five working days before the system is ready for inspection. 9. The permitting authority conducts the construction inspection and issues deficiency notice if needed.

How long does it take to get a building permit in unincorporated Knox County, TX?

Typical processing time is TCEQ states OSSF permit applications must be approved or denied within 30 days of receipt.

What work is exempt from building permits in unincorporated Knox County, TX?

The following work is generally exempt: The 10 acre rule: a permit may be exempt if all stated conditions are met, including the required site evaluation, single-family residential use on a tract of 10 acres or more, and the stated setback and on-site disposal conditions; Emergency OSSF repairs are not required to obtain a permit, but the repairs must be reported to the permitting authority in writing within 72 hours after repairs begin. Note: For OSSF only. No public county exempt-work list for general building work was found.

How do I schedule a building inspection in unincorporated Knox County, TX?

Inspections can be scheduled via: TCEQ Region 3. The installer must notify the permitting authority at least five working days before the date the system will be ready for inspection..