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§ 02
When a permit is required
Permit triggers and exempt work for King County
No public countywide general building permit requirement was found for unincorporated King County. Verified controls are narrower: floodplain permits required for development in mapped Special Flood Hazard Areas; OSSF permits required to construct, alter, repair, extend, and operate an on-site sewage facility unless exempt.
For OSSF: single-family dwelling on a tract of 10 acres or more if all 30 TAC 285 criteria are met (site evaluation, minimum setbacks, on-property effluent disposal, dwelling is the only dwelling on tract)
For OSSF: emergency repairs listed by TCEQ do not require a permit but must be reported in writing to the permitting authority within 72 hours after repairs begin
For OSSF: a grandfathered system may not need a permit if installed before the applicable local program date or before September 1, 1989, is not creating a nuisance, is not in need of repair, and has not had a significant increase in use or alteration
- Exempt For OSSF: single-family dwelling on a tract of 10 acres or more if all 30 TAC 285 criteria are met (site evaluation, minimum setbacks, on-property effluent disposal, dwelling is the only dwelling on tract)
- Exempt For OSSF: emergency repairs listed by TCEQ do not require a permit but must be reported in writing to the permitting authority within 72 hours after repairs begin
- Exempt For OSSF: a grandfathered system may not need a permit if installed before the applicable local program date or before September 1, 1989, is not creating a nuisance, is not in need of repair, and has not had a significant increase in use or alteration
Note: No general building permit exemptions list was found because no countywide general building permit program is publicly documented. Exempt from OSSF permit does not mean exempt from other regulatory overlays (floodplain, utility, etc.); confirm edge cases with King County Judge or TCEQ Region 2.
Required documents
- For OSSF: TCEQ-0235 permit application, owner information, site address and legal description, water source details, dwelling or business details, site evaluator information, installer information, soil/site evaluation documentation, planning materials if applicable
- Building code
- No public countywide adoption of a general building code (IBC/IRC) was found. King County has adopted minimum floodplain regulations under Texas Water Code Section 16.3145 and participates in the NFIP. OSSF work is governed by Texas Health and Safety Code Chapter 366 and 30 TAC Chapter 285.
- Permit validity
- OSSF authorization to construct is valid for one calendar year from issuance.
- Owner-builder
- For OSSF: an owner may install an OSSF for a single-family dwelling the owner owns on property the owner owns, provided the property is not being developed for sale or lease and all permitting, construction, and maintenance requirements are met.
- Contractor requirements
- For OSSF: site evaluations must be performed by a licensed Site Evaluator or Professional Engineer; installation must be performed by a licensed installer of the correct level, except for limited exceptions such as licensed electricians installing electrical components.
§ 03
Application process
Typical processing: OSSF review must be completed within 30 days of receipt. Floodplain timing not publicly posted.
- 01 Verify the parcel is in unincorporated King County.
- 02 Determine whether the project involves general building work, floodplain development, or OSSF work.
- 03 For floodplain development, contact the King County Judge / Floodplain Administrator if the site is in a mapped Special Flood Hazard Area.
- 04 For OSSF work, arrange a site evaluation by a licensed Site Evaluator or Professional Engineer.
- 05 Complete TCEQ-0235 OSSF permit application and assemble planning materials.
- 06 Submit the OSSF application and supporting documents to TCEQ Region 2.
- 07 TCEQ reviews the application and must approve or deny within 30 days of receipt.
- 08 After authorization to construct is issued, notify the permitting authority at least five working days before the system is ready for inspection.
- 09 Upon passing inspection, the permitting authority issues written approval.
Typical processing time: OSSF review must be completed within 30 days of receipt. Floodplain timing not publicly posted.
§ 04
Fee schedule
Effective Per TCEQ RG-472
Fee type
Amount
01
Minimum permit fee
$200 for single-family dwelling OSSF; $400 for non-single-family OSSF, plus $10 commission fee
02
Permit fee formula
Flat fee by OSSF type in TCEQ-administered areas
03
Reinspection fee
One-half of the original permit fee
04
Penalty (no permit)
Unauthorized construction can result in civil and/or administrative penalties; specific county penalty schedule not publicly available
OSSF fee payable when application is submitted to TCEQ regional office by check or money order payable to TCEQ. No online county payment process found.
Fees change periodically. Confirm at the official fee schedule ↗ (effective Per TCEQ RG-472) before budgeting.
§ 05
Required inspections
Scheduling and sequence
How to schedule
- Contact TCEQ Region 2 or King County Judge directly (in-person)
- Scheduling deadline
- For OSSF: permit holder / installer must notify the permitting authority at least five working days before the system is ready for inspection.
- Inspection hours
- TCEQ Region 2 office hours: Monday through Friday, 8:00 AM to 5:00 PM
Typical sequence: For OSSF: site evaluation and planning materials, application review, authorization to construct, construction, notice that system is ready, construction inspection, correction if needed, reinspection if needed, written notice of approval after passing.
§ 06
Frequently asked
Common questions about unincorporated King County permits
01 Do I need a building permit in unincorporated King County, TX? ▸
No public countywide general building permit requirement was found for unincorporated King County. Verified controls are narrower: floodplain permits required for development in mapped Special Flood Hazard Areas; OSSF permits required to construct, alter, repair, extend, and operate an on-site sewage facility unless exempt.
02 How much does a building permit cost in unincorporated King County, TX? ▸
Building permit fees in unincorporated King County, TX are set by the local building department and vary by project type and valuation. The minimum permit fee is $200 for single-family dwelling OSSF; $400 for non-single-family OSSF, plus $10 commission fee. Fees are calculated as: Flat fee by OSSF type in TCEQ-administered areas.
03 How do I apply for a building permit in unincorporated King County, TX? ▸
To apply for a building permit in unincorporated King County, TX, follow these steps: 1. Verify the parcel is in unincorporated King County. 2. Determine whether the project involves general building work, floodplain development, or OSSF work. 3. For floodplain development, contact the King County Judge / Floodplain Administrator if the site is in a mapped Special Flood Hazard Area. 4. For OSSF work, arrange a site evaluation by a licensed Site Evaluator or Professional Engineer. 5. Complete TCEQ-0235 OSSF permit application and assemble planning materials. 6. Submit the OSSF application and supporting documents to TCEQ Region 2. 7. TCEQ reviews the application and must approve or deny within 30 days of receipt. 8. After authorization to construct is issued, notify the permitting authority at least five working days before the system is ready for inspection. 9. Upon passing inspection, the permitting authority issues written approval.
04 How long does it take to get a building permit in unincorporated King County, TX? ▸
Building permit processing times in unincorporated King County, TX typically run OSSF review must be completed within 30 days of receipt. Floodplain timing not publicly posted.. Timelines can vary based on project complexity and current department workload.
05 What work is exempt from building permits in unincorporated King County, TX? ▸
Not all construction work requires a permit in unincorporated King County, TX. The following work is generally exempt: For OSSF: single-family dwelling on a tract of 10 acres or more if all 30 TAC 285 criteria are met (site evaluation, minimum setbacks, on-property effluent disposal, dwelling is the only dwelling on tract); For OSSF: emergency repairs listed by TCEQ do not require a permit but must be reported in writing to the permitting authority within 72 hours after repairs begin; For OSSF: a grandfathered system may not need a permit if installed before the applicable local program date or before September 1, 1989, is not creating a nuisance, is not in need of repair, and has not had a significant increase in use or alteration. Note: No general building permit exemptions list was found because no countywide general building permit program is publicly documented. Exempt from OSSF permit does not mean exempt from other regulatory overlays (floodplain, utility, etc.); confirm edge cases with King County Judge or TCEQ Region 2. When in doubt, confirm with the local building department before starting work.
06 How do I schedule a building inspection in unincorporated King County, TX? ▸
Once your permit is issued and work reaches an inspection milestone, you can schedule a building inspection in unincorporated King County, TX via: Contact TCEQ Region 2 or King County Judge directly. For OSSF: permit holder / installer must notify the permitting authority at least five working days before the system is ready for inspection..
last verified April 2026
source King County Judge / Floodplain Administrator; Texas Commission on Environmental Quality (TCEQ) Region 2 OSSF Program ↗
entry id permits/texas/king/unincorporated
Educational reference. Permit rules and fees change — confirm current requirements directly with King County Judge / Floodplain Administrator; Texas Commission on Environmental Quality (TCEQ) Region 2 OSSF Program before applying. Jaspector is not legal advice.