Building permits, zoning and land rules in Johnson County, Missouri

At a glance

Building permit

Not required in unincorporated areas, except properties inside the Whiteman Air Force Base Zoning Area¹²

Zoning

None outside the Whiteman AFB Zoning Area; contact the Military Airport Zoning Commission to check that area⁶²

Septic permits

Johnson County Community Health Services - Environmental Health; required for new construction or modification of any OWTS⁷⁵

Owner-builder

You can build your own home since there's no county permit to be exempt from; state trade licensing may still apply³

Floodplain

State and federal rules apply; flood plain maps and construction permits for flood hazard areas are at the Assessor's Office²

Well permit

A non-restricted well installation permit is required for contracted work; landowners may install their own well without a permit⁸

Subdivision covenants

Land inside a platted subdivision may carry private restrictions and covenants, recorded with the County Recorder⁹

Septic soil difficulty

0% of county soils are free of severe limits for a conventional drain field¹⁰

Who to call

Contact details are copied from each office’s official page and were checked against it on September 23, 2026.

Do you need a building permit in Johnson County, Missouri?

No, for almost all unincorporated land. Johnson County states outright that it "does not have planning and zoning regulations, building codes, building permits, inspections, or occupancy certificates for unincorporated areas," and hands out a printable "No Planning and Zoning" letter signed by the county commissioners for anyone who needs to prove it². The one carve-out is land inside the Whiteman Air Force Base Zoning Area, where the Military Airport Zoning Commission has its own rules; contact the Military Airport Zoning Commission to check whether your parcel is inside that area². If your land is inside an incorporated city, that city's own zoning and building ordinances take over instead of the county's². Building in a mapped flood hazard area is another exception: state and federal rules still apply, and construction permits for those areas come from the county Assessor's Office¹¹.

Who handles floodplain, septic and right-of-way questions in Johnson County?

There's no building department to call, but three offices matter for land outside the cities and the Whiteman AFB zoning area. The Johnson County Assessor's Office provides flood plain maps and issues construction permits for flood hazard areas, and also assigns the address and road number for property in the unincorporated county¹¹. Johnson County Community Health Services, Environmental Health, administers and permits every onsite wastewater treatment system in the county¹²⁴. For construction within 30 feet of the center of a county road or trail, contact the County Clerk's Office for right-of-way procedures and an application¹³. A driveway connecting to a county road follows a separate driveway permit application with its own specifications².

Does Johnson County have zoning?

No, outside the Whiteman Air Force Base Zoning Area. The county states plainly that it has no planning and zoning regulations for unincorporated land, so there's no minimum dwelling size, minimum lot size, setback, lot-coverage limit or building-height limit set by the county^149151617. Two things still narrow that freedom in practice: land inside a platted subdivision may carry private restrictions and covenants, recorded with the county Recorder, and land inside an incorporated city follows that city's zoning ordinance instead⁹². Missouri counties can adopt zoning and building authority if they choose to, so this reflects a county decision rather than a state ban¹⁸¹⁹.

How do septic permits work in Johnson County?

Johnson County Community Health Services is the county's designated administrator for the design, construction and major modification of every onsite wastewater treatment system (OWTS), and a permit is required for new construction or any modification⁴⁵. Soils here make that permit essential groundwork rather than paperwork: zero percent of Johnson County's land is free of severe limitations for a conventional drain field, so expect a site evaluation to steer you toward an alternative or engineered system almost everywhere in the county¹⁰. Missouri doesn't require an inspection or evaluation of an existing system before a sale unless a lender or buyer asks for one, though some counties add their own transaction rule, so confirm Johnson County's practice with Environmental Health directly²⁰. Wastewater can't legally be discharged into a road ditch or onto the ground; whatever system you install has to avoid posing a threat to public health or the environment²¹.

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

With no county planning and zoning regulations on unincorporated land, Johnson County sets no minimum dwelling size and no zoning district rule that would separately restrict how you occupy your own property¹⁴. That's a real advantage over counties with active zoning, but the county's own guidance doesn't specifically confirm rules for RVs, tiny homes or manufactured homes beyond that general absence, so it's worth a direct call before you commit to a plan. Whatever you build, remember septic is still mandatory and permitted through Environmental Health if you're not on a public sewer connection⁵¹².

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

First, confirm your parcel isn't inside the Whiteman Air Force Base Zoning Area or a city limit, since either one brings its own permit and zoning rules; contact the Military Airport Zoning Commission for the zoning area, or check with the relevant city hall². Next, check whether your land is in a mapped flood hazard area at the Assessor's Office, since that's the one place a county construction permit still applies¹¹. Get a septic site evaluation early given how limited the county's soils are for a conventional system, then apply for your OWTS permit through Environmental Health before installation or modification begins¹⁰¹²⁵. If your driveway connects to a county road, complete the driveway permit application, and if construction comes within 30 feet of the center of a county road or trail, get right-of-way approval from the County Clerk's Office¹³. If you need a well, note that a non-restricted well installation permit is required unless you're installing it yourself as the landowner⁸. Finally, build: no county building-permit review applies to an ordinary single-family home in most of unincorporated Johnson County¹.

What to check before you buy land in Johnson County

Septic is the headline issue here: 0% of the county's soils are free of severe limitations for a conventional drain field, so budget for a site evaluation and likely an engineered system before you count on any parcel being buildable¹⁰. The land itself is gentle, with 97.2% of the county at 15% slope or less, and moderately wooded at 24.9% forest, so terrain rarely limits where you can build²²²³. Check whether the property is inside the Whiteman Air Force Base Zoning Area or an incorporated city limit before assuming the county's no-permit, no-zoning picture applies, since both change the rules². If the tract is in a platted subdivision, ask the county Recorder for a copy of any restrictions and covenants that run with the land⁹. Typical property tax runs about 0.7% effectively, with a median bill near $1,515 a year, on a typical home value around $287,697²⁴²⁵²⁶.

Watch-outs

• Johnson County exists in many states, including Kansas, Indiana, Iowa, Texas and Arkansas; confirm you're looking at Johnson County, Missouri (Warrensburg, west-central Missouri near Whiteman Air Force Base) before trusting a search result².
• The county's no-permit, no-zoning statement carries one real exception: land inside the Whiteman Air Force Base Zoning Area is subject to the Military Airport Zoning Commission's own rules, so always confirm your parcel's location before assuming no restrictions apply².

Sources

1. Planning & Zoning (2026 county census)
2. Planning & Zoning, quoted and re-checked
3. Planning & Zoning (2026 county census)
4. Wastewater Treatment, quoted and re-checked
5. Wastewater Treatment, quoted and re-checked
6. Johnson County MO EDC - Licensing/Permits (2026 county census)
7. Wastewater Treatment (2026 county census)
8. Water Wells - PUB2945, quoted and re-checked
9. Planning & Zoning, quoted and re-checked
10. Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
11. Johnson County Assessor's Office (jocomo.gov)
12. Johnson County Community Health Services, Environmental Health (johnsoncountyhealth.org)
13. Johnson County Clerk's Office (jocomo.gov)
14. Planning & Zoning, quoted and re-checked
15. Planning & Zoning, quoted and re-checked
16. Planning & Zoning, quoted and re-checked
17. Planning & Zoning, quoted and re-checked
18. RSMo § 64.090 — Planning and zoning powers of county commission (Missouri statewide rule), quoted and re-checked
19. RSMo § 64.170 — County commissions control construction and issue building permits (Missouri statewide rule), quoted and re-checked
20. Frequently Asked Questions, quoted and re-checked
21. Wastewater Treatment, quoted and re-checked
22. Share of land at 15% slope or less: Bolthole Index county data
23. Wooded share of land: Bolthole Index county data
24. Effective property tax rate: Bolthole Index county data
25. Median property tax bill: Bolthole Index county data
26. Typical home value (Zillow): Bolthole Index county data

Written September 23, 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.