Unincorporated Ralls County, Missouri requires county zoning and development approval, but we could not confirm a full residential building-code permit program12. Buildings that require a wastewater permit also need a certificate of occupancy and a county compliance inspection before occupancy34. Septic construction is permitted through the Ralls County Health Department5.
At a glance
- Building permit
- Limited county construction and zoning approval; a full building-code permit program was not confirmed1
- Zoning
- Yes, for unincorporated Ralls County2
- Septic permit
- Required through the Ralls County Health Department65
- Certificate of occupancy
- Required for a building that requires a wastewater permit3
- RV living
- General private-land occupancy was not confirmed; ask Planning & Zoning7
- Tiny homes
- No specific occupancy rule or minimum dwelling size was confirmed; zoning still applies27
- Owner-builder
- No county owner-builder exemption was confirmed8
- Minimum lot size
- District-specific; reviewed single-family standards generally require 3 acres9
Who to call
Planning & zoning
Ralls County Planning & Zoning
Zoning, construction applications and land-use questions in unincorporated Ralls County
311 S. Main Street, New London, MO 63459
Septic permits
Ralls County Health Department
Domestic onsite sewage permits and environmental health questions
16369 Business 61, New London, MO 63459
Floodplain permits
County floodplain questions, county roads, culverts and driveway pipes
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 Ralls County, Missouri?
Unincorporated Ralls County uses a limited county approval system: Planning & Zoning administers land-use and construction requirements, but the reviewed material did not confirm a full residential building-code inspection program1. Missouri fire and building codes are adopted locally rather than through one uniform statewide building code10. County zoning applies to all unincorporated land, so a rural parcel is not unrestricted2. A building that requires a wastewater permit cannot be occupied until the county issues a certificate of occupancy, and the county inspects that permitted structure for compliance with its zoning order before issuing the certificate34. Ralls County Planning & Zoning accepts applications by appointment, so call before bringing in plans7. We could not confirm a general owner-builder exemption; an owner planning to perform the work should ask Planning & Zoning what applications and contractor information apply87.
Who handles building permits in Ralls County, Missouri?
Ralls County Planning & Zoning is the first stop for construction and land-use approval in unincorporated Ralls County17. The office can be reached at 573-822-4608 or [email protected], and applications are by appointment7. Ask the office to identify the parcel's zoning district, permitted residential use, setbacks, wastewater-related occupancy requirements and the current construction application for the proposed work111237. The reviewed county material does not establish one general building-code fee schedule, so request the current fees with the application. Development in the county Flood Plain District has extra land-use limits layered over the underlying zoning district; Road & Bridge provides the county floodplain contact1314. If access enters a state-maintained highway, MoDOT requires a permit to construct or modify a driveway within its right-of-way15.
Does Ralls County, Missouri have zoning?
Yes. Ralls County zoning covers unincorporated land, while incorporated cities, towns and villages are outside that county zoning geography2. The published county system includes agricultural, residential, recreational-residential and floodplain districts, with different standards by district and use11. The reviewed single-family standards require a 3-acre lot in both the agricultural and residential districts; a residential lot tied directly to an approved central sewer may use a 15,000-square-foot minimum9. Setbacks also differ: the reviewed agricultural single-family standard is 80 feet in front, 50 feet at the side and 80 feet at the rear, while the reviewed residential standard is 40 feet in front, 30 feet at the side and 80 feet at the rear12. These figures cannot be applied until Planning & Zoning confirms the parcel's district and proposed use117. A land division also needs final-plat approval before recording when the county subdivision rules apply16.
How do septic permits work in Ralls County, Missouri?
Ralls County Health Department administers permits for domestic onsite sewage systems5. A county permit is required to construct, install, modify, replace, repair or operate a covered wastewater treatment system, and the reviewed construction-permit fee is $115, subject to annual revision6. The installation generally must remain uncovered for county inspection unless the department authorizes covering or backfilling before approval17. Only about 1.7% of Ralls County soils are rated without severe limits for a conventional septic drain field, so make a site and soil evaluation an early purchase contingency18. Where an approved sewer is not reasonably accessible, an individual system may be allowed only when the lot has enough area and the applicable county, state and federal requirements are met19. Missouri splits wastewater authority by system type and flow, with larger or discharging systems potentially falling under the Department of Natural Resources rather than the local program20.
Can you live in an RV or tiny home in Ralls County, Missouri?
We could not confirm a general rule allowing long-term residential RV occupancy on a private parcel in unincorporated Ralls County, so ask Planning & Zoning about the parcel, duration, utilities and wastewater plan before relying on an RV7. The county's rules for campgrounds or trailer parks do not by themselves answer whether one RV may be occupied as a residence on ordinary private land. We also could not confirm a specific tiny-home occupancy rule or a countywide minimum dwelling floor area. A tiny home still has to fit the parcel's zoning district, lot-size and setback standards, and any building requiring a wastewater permit needs a certificate of occupancy before someone moves in29123. Off-grid sanitation is not a way around sewage review: when no approved sewer is accessible, the individual disposal system still needs adequate lot area and the required approvals19.
What are the steps to build a home in Ralls County, Missouri?
- Ask Ralls County Planning & Zoning to confirm that the parcel is in unincorporated territory, identify its zoning district and verify that the dwelling use, lot size and setbacks fit29127.
- Have the Ralls County Health Department evaluate the onsite wastewater plan and obtain the required construction permit before septic work begins621.
- Ask Road & Bridge about floodplain constraints and county-road access; obtain a MoDOT permit if the driveway enters state right-of-way131415.
- Submit the current construction or zoning application to Planning & Zoning by appointment17.
- Keep the septic installation open for inspection unless the Health Department authorizes otherwise17.
- Complete the county compliance inspection and obtain the certificate of occupancy before occupying a building that requires a wastewater permit43.
What should you check before buying land in Ralls County?
Confirm zoning and septic feasibility before treating acreage as buildable. Ralls County's unincorporated land is zoned, and the applicable lot size and setbacks depend on the district and use2912. Septic deserves special attention because only about 1.7% of county soils are rated without severe limits for a conventional drain field18. About 82.4% of county land has a slope of 15% or less, but gentle terrain does not establish septic suitability2218. Check the floodplain overlay and legal road access before fixing a house site; county floodplain rules layer onto the underlying district, and a driveway in MoDOT right-of-way needs state approval1315. We could not confirm a county private-well permit rule, so ask the Health Department what water-supply review applies. The effective property-tax rate is about 0.8%, with a median annual property-tax bill of about $1,1612324.
Watch-outs
- Rural land in unincorporated Ralls County is zoned; confirm the district before relying on acreage, setbacks or an intended use211.
- Only about 1.7% of county soils are rated without severe limits for a conventional septic drain field, so make onsite wastewater approval a purchase contingency186.
- We could not confirm general permission for residential RV use, a tiny-home rule, a minimum dwelling floor area, a private-well permit rule or an owner-builder exemption; ask Planning & Zoning and the Health Department before committing to those plans7218.
Sources
- Ralls County Missouri - Planning & Zoning (2026 county census)
- Planning & Zoning – Ralls County Missouri, quoted and re-checked
- Ralls County Planning and Zoning Order, quoted and re-checked
- Ralls County Planning and Zoning Order, quoted and re-checked
- Ralls County Health Department - Environmental (2026 county census)
- Ralls County Planning and Zoning Order, quoted and re-checked
- Ralls County Planning & Zoning (rallscountymo.gov)
- (2026 county census)
- Ralls County Planning and Zoning Order, quoted and re-checked
- RSMo Section 64.170 (Missouri statewide rule), quoted and re-checked
- Ralls County Planning and Zoning Order, quoted and re-checked
- Ralls County Planning and Zoning Order, quoted and re-checked
- Ralls County Planning and Zoning Order, quoted and re-checked
- Ralls County Road & Bridge (rallscountymo.gov)
- Permits | Missouri Department of Transportation (Missouri statewide rule), quoted and re-checked
- Ralls County Planning and Zoning Order, quoted and re-checked
- Ralls County Planning and Zoning Order, quoted and re-checked
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- Ralls County Planning and Zoning Order, quoted and re-checked
- On-site Septic Systems and Subdivisions (Missouri statewide rule), quoted and re-checked
- Ralls County Health Department (rallscountyhealth.org)
- Share of land at 15% slope or less: 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.