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

No building or occupancy permit is required for construction in unincorporated Callaway County¹. There is therefore no county building-permit application process to complete, and an owner-builder may construct a home without seeking an exemption from such a permit¹. We could not confirm whether Callaway County has formally adopted a building code or conducts separate building inspections, so ask the County Commission if either point affects your project. Separate permits still apply to specific work: obtain a Right-of-Way Access Permit before constructing a driveway entrance on a county-maintained road, and obtain a Utility Right-of-Way permit before taking water, telephone, or electrical lines across a county road^1,6. Incorporated cities and villages may impose their own building, occupancy, planning, and zoning requirements⁴.

Callaway County does not publish a building-permit process for unincorporated construction because no county building or occupancy permit is required there¹. For sewage-ordinance questions, the county-published contact is reachable at 573-491-1118¹. The Callaway County Sewer District is the contact point for onsite septic permitting across its coverage area, which excludes places regulated by the Public Service Commission or another wastewater provider⁵. For mapped flood-hazard land, the county's floodplain-ordinance contact is reachable at 573-592-2480¹. The Road and Bridge Engineer at 573-642-0740 handles driveway access and utility-line crossings of county roads¹. Before applying anywhere, confirm that the parcel is outside an incorporated city or village because local municipal permit processes may replace the unincorporated-county answer⁴.

Callaway County has not adopted county-administered planning or zoning¹. Unincorporated Callaway County consequently sets no zoning-based minimum dwelling size, minimum lot size, setbacks, lot-coverage limit, or building-height limit¹. Those answers do not override septic, floodplain, road-right-of-way, or stormwater controls. Inside the county's MS4 stormwater area, land development disturbing 1 acre or more—and smaller work within a larger common plan—falls under county stormwater rules; qualifying projects used exclusively for agriculture or silviculture are exempt from those MS4 rules⁹. Zoning varies inside incorporated places, including Fulton, Holts Summit, Lake Mykee, New Bloomfield, Mokane, Kingdom City, and Auxvasse, so verify municipal rules when a parcel lies within city or village limits⁴.

The Callaway County Sewer District is the contact point for onsite septic permitting in its coverage area, which spans the county except places regulated by the Public Service Commission or another wastewater provider⁵. Every single-home onsite system in that coverage area needs a permit to install or upgrade, and contractors must notify the district at least 24 hours before performing the work². Callaway County also operates under a local onsite-wastewater ordinance that may be stricter than Missouri's minimum standards; some incorporated places may instead send applicants to the state¹⁰. Only 0.1% of county soils are rated free of severe limitations for a conventional drain field, so establish system feasibility and cost before committing to a house site⁸. Missouri allows onsite wastewater systems where central sewer is unavailable, but the system must receive the applicable approval and meet state and stricter local standards¹¹. For an existing system, a private licensed inspector can assess its condition because local health agencies generally no longer inspect systems for real-estate transfers¹².

Unincorporated Callaway County has no county zoning rule restricting full-time RV living, temporary camping, tiny-home occupancy, manufactured-home occupancy, or accessory dwellings¹. That freedom is limited to county zoning: an occupied RV, tiny home, manufactured home, or accessory dwelling still needs a lawful sanitation arrangement. Missouri permits onsite wastewater treatment where central sewer is unavailable, subject to applicable approval and state or stricter local standards¹¹. The county's own sanitation finding is limited to onsite wastewater systems; we could not confirm whether another off-grid sanitation method is allowed, so ask the sewage-ordinance contact before planning one^1,13. Placement of a manufactured home or other development in mapped county flood-hazard areas requires a floodplain development permit before work begins³. Incorporated cities and villages may apply their own zoning, building-permit, and occupancy-permit rules⁴.

1. Confirm whether the parcel is unincorporated or inside a municipality, because city and village rules vary⁴.

1. Contact the Callaway County Sewer District, identify the wastewater provider for the parcel, and secure the required single-home onsite-system permit before installation or an upgrade^2,5.

1. Check the flood map; mapped county flood-hazard development needs a separate permit before work begins³.

1. Obtain Road and Bridge approval before constructing a driveway entrance on a county-maintained road, and obtain a Utility Right-of-Way permit only if a utility line will cross a county road^1,6.

1. Arrange water. A landowner may install a personal well or pump without the contractor permit otherwise required for regulated well work⁷.

1. Build without a county building or occupancy permit if the site is in unincorporated Callaway County, while separately satisfying every applicable septic, floodplain, road, and stormwater rule¹.

Start with septic feasibility: only 0.1% of Callaway County soils are rated free of severe limitations for a conventional drain field⁸. Ask the Sewer District which wastewater provider covers the parcel and what the proposed house site can support before treating land as buildable⁵. Check the flood map as well, because proposed construction and other development in the county's mapped A and AE flood zones requires a floodplain development permit³. Verify legal access and whether a new entrance touches a county-maintained road; driveway location and culvert details require Road and Bridge approval before construction⁶. For larger projects in the MS4 stormwater area, development disturbing 1 acre or more—or smaller work within a larger common plan—falls under county stormwater rules⁹. Countywide subdivision requirements outside that area remain unconfirmed, so ask the County Commission before dividing a tract. Typical property tax is about 0.8%, with a median annual bill near $1,549⁸.