Unincorporated Simpson County, Kentucky requires a building permit, and the county's residential permit process includes foundation, framing and final inspections12. Zoning also applies across the unincorporated county, while septic site evaluations, permits and inspections go through the Barren River District Health Department34. Start with Planning and Zoning before choosing a house plan or assuming a rural parcel can support the use you want.
At a glance
- Building permit
- Required through Simpson County Planning and Zoning1
- Building inspections
- Foundation, framing and final inspections are identified in the residential permit process2
- Zoning
- Applies throughout unincorporated Simpson County3
- Septic permit
- Required through Barren River District Health Department45
- RV living
- Not confirmed for long-term occupancy on private land; ask Planning and Zoning6
- Tiny home
- No distinct county occupancy rule confirmed; zoning and building review still apply13
- Private well work
- Must be performed by a Kentucky-certified water-well driller or assistant7
Who to call
Building permits
Simpson County Planning and Zoning
Building permits, inspections and zoning for Simpson County
100 Courthouse Sq, Franklin, KY 42134
Septic permits
Barren River District Health Department Onsite Sewage Program
Onsite soil evaluations, septic-system plan review, permits and inspections for Simpson County
1109 State Street, Bowling Green, KY 42101
Roads & driveways
Simpson County Road/Public Works Department
County-road infrastructure and questions about entrances connecting to county-maintained roads
2724 Kenneth Utley Drive, Franklin, KY 42134
Contact details are copied from each office’s official page and were checked against it on September 27, 2026.
Do you need a building permit in Simpson County, Kentucky?
Yes. Unincorporated Simpson County requires building permits, and Simpson County Planning and Zoning has a Chief Building Official who administers the local process18. The residential permit materials identify foundation, framing and final inspections, so plan for review during construction rather than treating the permit as a one-time filing2. Kentucky otherwise does not require permits, inspections or certificates of occupancy for a single-family dwelling unless a local ordinance requires them; Simpson County's local permit program is what changes that default here91. Published fee schedules are linked from the county permits page, but current amounts were not established, so ask Planning and Zoning for the fee tied to your exact project10.
Who is the Simpson County building department, and how do you reach it?
Simpson County Planning and Zoning is the building and zoning office: call 270-586-3356 or visit 100 Courthouse Sq, Franklin, KY 421348. The county also provides an online application portal where applicants can apply for and pay for permits, then contact the office for a fee invoice8. For county-road access, contact the Simpson County Road/Public Works Department at 270-586-4294, 2724 Kenneth Utley Drive, Franklin, KY 4213411. A proposed entrance onto a county-maintained road must be inspected and approved before installation; an owner may install the entrance tile, but approval still comes first12. For an entrance onto a state highway, the owner instead applies in writing to the Kentucky Department of Highways district engineer13.
Does Simpson County, Kentucky have zoning?
Yes. Simpson County's zoning regulations apply to all property in the unincorporated county, and the same regulations also apply in the City of Franklin3. Other incorporated municipalities should be checked separately before relying on the county rules14. The regulations publish multiple residential districts, including single-family, two-family and manufactured-home districts, so a use that is acceptable in one district may not be acceptable on another parcel15. Dividing land for eventual lot development also brings the subdivision regulations into play in addition to zoning16. We could not confirm a general county minimum dwelling size or a single countywide setback from the available rules; ask Planning and Zoning to identify the parcel's district, map designation and dimensional table before designing the site plan8.
How do septic permits work in Simpson County?
The Barren River District Health Department handles onsite sewage work for Simpson County, including soil evaluations, installation-plan review, permits and inspections417. Kentucky requires a permit before any portion of an onsite sewage system is constructed, installed or altered; the permit follows a site evaluation and is issued to a certified installer or homeowner5. Every installed, constructed, altered or repaired onsite system must be inspected by a certified inspector before backfilling, subject to the regulation's installer-affidavit procedure18. About 69.1% of Simpson County soils are rated without severe limits for a conventional drain field, but that countywide figure does not replace the parcel-specific evaluation19. Where public sewer is unavailable, a building's house drain must connect to an approved private sewage-disposal system20.
Can you live in an RV or tiny home on your land in Simpson County?
Long-term RV occupancy on private land in Simpson County could not be confirmed from the available county rules, so ask Planning and Zoning about the parcel's district and whether temporary occupancy during construction is allowed8. Kentucky's rule allowing a person to sleep temporarily in a lawfully parked vehicle for less than 12 hours on a public road, street or parking lot does not authorize permanent RV living on private land6. Tiny homes are not identified as a distinct occupancy category in the confirmed county material. A tiny home project should therefore be taken to Planning and Zoning as a dwelling proposal subject to the county building-permit process and the parcel's zoning district115. Simpson County's permit materials do not state an owner-builder exemption, so owner-builders should ask the office what work they may perform and which licensed trades are required21.
Building a home in Simpson County: the steps, in order
- Ask Simpson County Planning and Zoning to confirm the parcel's zoning district and the allowed dwelling type before finalizing a plan158.
- Have the Barren River District Health Department evaluate the site and obtain the onsite sewage permit before any septic construction begins175.
- Apply for the Simpson County building permit and confirm the current fees with Planning and Zoning110.
- Arrange the required foundation, framing and final building inspections as work progresses2.
- Obtain approval before installing an entrance onto a county-maintained road; use the state district-engineer process instead if the entrance meets a state highway1213.
- Keep the septic system uncovered until its required inspection is complete18.
- If the site lies in an identified floodplain, obtain both state and local floodplain permits before development22.
What should you check before buying land in Simpson County?
Start with zoning, septic and access. Simpson County zoning reaches the unincorporated county, and the correct residential district determines which dimensional and use rules govern the parcel315. A county-road entrance needs inspection and approval before installation, while land in an identified floodplain needs both state and local floodplain permits1222. Terrain is broadly favorable: about 91.1% of county land is at a slope of 15% or less, while about 69.1% of soils are rated without severe limits for a conventional septic drain field2319. Simpson County averages about 51.5 inches of annual precipitation24. Carrying costs average about a 0.6% effective property-tax rate and a $1,246 median annual property-tax bill, but verify the actual assessment and any deed restrictions for the parcel2526.
Watch-outs
- A rural address does not mean a parcel is outside zoning: Simpson County's regulations cover the unincorporated county, and the specific district controls the permitted use315.
- Do not install or backfill a septic system before the permit and inspection steps are complete518.
- Development in an identified Kentucky floodplain requires both a state permit and a local floodplain permit22.
- Long-term RV living, tiny-home occupancy and a general minimum dwelling size remain unconfirmed; ask Simpson County Planning and Zoning about the specific parcel before purchase8.
Sources
- Simpson County Planning and Zoning (2026 county census)
- Simpson County Zoning Regulations—Building Permits and Procedures, quoted and re-checked
- Simpson County Zoning Regulations, quoted and re-checked
- Barren River District Health Department Onsite Sewage (2026 county census)
- 902 KAR 10:110. Issuance of on-site sewage disposal system permits (Kentucky statewide rule), quoted and re-checked
- KRS 511.110 — Unlawful camping (Kentucky statewide rule), quoted and re-checked
- 401 KAR 6:320. Certification of water well drillers and water well driller assistants (Kentucky statewide rule), quoted and re-checked
- Simpson County Planning and Zoning (simpsoncountyky.gov)
- 815 KAR 7:125, Kentucky Residential Code (Kentucky statewide rule), quoted and re-checked
- Permits and Forms, quoted and re-checked
- Simpson County Road/Public Works Department (simpsoncountyky.gov)
- Simpson County Road Connection Permit, quoted and re-checked
- 603 KAR 1:020 Driveway approaches, entrances; construction and maintenance (Kentucky statewide rule), quoted and re-checked
- Simpson County Zoning Regulations (2026 county census)
- Simpson County Zoning Regulations, quoted and re-checked
- Simpson County Zoning Regulations, quoted and re-checked
- Barren River District Health Department Onsite Sewage Program (barrenriverhealth.org)
- 902 KAR 10:085. System Installation Inspection (Kentucky statewide rule), quoted and re-checked
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- 815 KAR 20:130. House sewers and storm water piping; methods of installation (Kentucky statewide rule), quoted and re-checked
- (2026 county census)
- Find Your Flood Zone (Kentucky statewide rule), quoted and re-checked
- Share of land at 15% slope or less: Bolthole Index county data
- Annual precipitation: Bolthole Index county data
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
Written September 27, 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.