Bolthole Index

Jefferson County, Missouri

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

52Index Score / 100
#109 of 115 in Missouri

Unincorporated Jefferson County, Missouri requires building permits for regulated construction and enforces locally amended building codes12. The county Planning Division sets zoning and setbacks, and Code Enforcement issues both building permits and septic permits3456. Incorporated cities may run their own rules, and the state health department handles septic permits inside them78.

At a glance

Building permit
Required for regulated work in unincorporated Jefferson County; apply through the Citizen Portal1910
Building code
2015 International Residential Code and related 2015 codes, plus county amendments (Chapter 500)211
Zoning
Yes: the Unified Development Order regulates development in unincorporated areas71213
Septic permits
County Code Enforcement on unincorporated land; DHSS inside incorporated areas1468
Septic soils
Only 2.3% of the county's soils are free of severe limits for a conventional drain field15
Small sheds
No building permit for a one-story detached storage shed up to 200 sq ft16
Driveways
County permit on county right-of-way; MoDOT permit on state right-of-way171819
RV living
An RV generally cannot be a residence; limited park and construction exceptions apply20

Who to call

Building permits

Jefferson County Code Enforcement Division

Building, electrical, plumbing, mechanical and sewer permits and inspections, and contractor licenses, for unincorporated Jefferson County; open Monday through Friday 7:30 am to 5 pm

636-797-5310

725 Maple Street, Hillsboro, MO 63050

Online permits →

Building permits

Jefferson County Code Enforcement Division (Building Permit Application)

The county's building permit application form and Licensed Contractor Verification Form

636-797-5310

buildingpermits@jeffcomo.org

725 Maple Street, Hillsboro, MO 63050

Online permits →

Codes & inspections

Jefferson County Code Enforcement Division (Codes & Ordinances)

Lists the building, sewage and floodplain codes in effect in unincorporated Jefferson County

725 Maple Street, Hillsboro, MO 63050

Codes & inspections

Jefferson County Code Enforcement Division (Permit FAQs)

The county's list of work that does not need a building permit

Codes & inspections

Jefferson County Building Code Fee Schedule (Section 500.250)

Building, sewage and manufactured-home permit fees adopted by Ordinance 21-0356

Septic permits

Jefferson County Code Enforcement Division (On-Site Sewage Treatment System Permits)

Onsite sewage (septic) permits, plan review and septic inspections in unincorporated Jefferson County

636-797-5310

buildingpermits@jeffcomo.org

725 Maple Street, Hillsboro, MO 63050

Online permits →

Health department

Missouri Department of Health and Senior Services, Onsite Wastewater Treatment Program

State onsite wastewater program; its county lookup names Jefferson County Code Enforcement as the county's septic permitting authority, and DHSS handles permits inside incorporated areas the county ordinance does not cover

573-751-6095

OnsiteProgram@health.mo.gov

PO Box 570, Jefferson City, MO 65102-0570

Planning & zoning

Jefferson County Planning Division

Zoning, zone changes, conditional uses, variances, plats and site development plans for unincorporated Jefferson County; open Monday through Friday 8 am to 5 pm

636-797-5580

725 Maple Street, Hillsboro, MO 63050

Online permits →

Zoning

Jefferson County Planning Division (Unified Development Order)

The county zoning code (Unified Development Order) and its ongoing rewrite

725 Maple Street, Hillsboro, MO 63050

Zoning

Jefferson County Planning Division (Development Review)

Setback questions, plat review and site development plan review

725 Maple Street, Hillsboro, MO 63050

Floodplain permits

Jefferson County Code Enforcement Division (Floodplain Development Permits)

Floodplain development permits in special flood hazard areas of unincorporated Jefferson County

Online permits →

Roads & driveways

Jefferson County Department of Public Works

Driveway permits on county right-of-way, land disturbance permits and other county road permits

636-797-5340

pworks@jeffcomo.org

725 Maple Street, Room 104, Hillsboro, MO 63050

Contact details are copied from each office’s official page and were checked against it on October 13, 2026.

Off-grid gear

Going off-grid in Jefferson County means bringing your own water and power. The kit we’d start with:

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

Yes. Unincorporated Jefferson County, Missouri requires building permits for regulated construction1. Jefferson County has adopted the 2015 International Residential Code and International Building Code, plus the fire, fuel gas, mechanical, plumbing and energy conservation codes and a county electrical code, all subject to local amendments in Chapter 50021121. Code Enforcement regulates construction, alteration and occupancy in unincorporated areas5. Applications go through the Citizen Portal, where users can submit permits, schedule inspections and check status after registering online first910.

A one-story detached storage shed no larger than 200 square feet, a fence no higher than 8 feet and a grade-supported water tank within the county's stated limits do not need a building permit16. Jefferson County requires inspections before framing, electrical, plumbing, mechanical or drain systems are covered or used; request inspections at least one business day ahead22. Final inspection follows finish grading and completion23. Ask Code Enforcement before treating a barn, workshop or other accessory structure as exempt.

Who issues building permits in Jefferson County, and how do you reach them?

The Jefferson County building department is the Code Enforcement Division at 725 Maple Street in Hillsboro, phone 636-797-5310, open Monday through Friday from 7:30 am to 5 pm5. Jefferson County's building-permit fee schedule took effect September 6, 2021; ask Code Enforcement for the total for your project24.

A qualifying owner or immediate-family member may receive a homeowner permit for work on an owner-occupied detached single-family home or accessory structure, but this is not a waiver of permits, plans, fees or inspections25. The permit holder must personally perform the work, pass the required written test with at least 75%, keep only one such permit open, and complete the work within the permit's one-year validity25. The building application still requires verification for the homeowner or general contractor and applicable licensed trades26.

County building rules apply to unincorporated Jefferson County; Hillsboro administers its own residential building permits inside city limits727. Septic permits inside incorporated areas go to the Missouri Department of Health and Senior Services (DHSS)8.

Does Jefferson County, Missouri have zoning?

Jefferson County applies its Unified Development Order to unincorporated land3. Crystal City and Hillsboro have their own zoning; septic permits inside incorporated areas go to DHSS28298. District-specific controls apply, and every unincorporated parcel has property-line setbacks based on its zoning district and lot shape12134.

Accessory dwelling units are allowed in residential zoning districts, including planned and non-planned districts and the PM Planned Mixed Use District, but they must be permanent, obtain a building permit, meet the principal use's setbacks and have off-driveway parking30. An accessory dwelling cannot be sold separately; a mobile home can serve as one only in the RA-5 and LR-2 districts30. Minimum lot size depends on the zoning district: 5 acres in RA-5, 2 acres in LR-2, and 40,000, 20,000, 10,000 or 7,000 square feet in R-40, R-20, R-10 and R-731. We could not confirm minimum dwelling sizes, lot coverage or complete height limits; give Planning the parcel number and proposal before relying on a listing.

How do septic permits work in Jefferson County, and who issues them?

Jefferson County Code Enforcement administers onsite sewage permits and inspections in unincorporated Jefferson County146. Construction cannot begin until Code Enforcement issues the septic permit32. Jefferson County septic applications require bedroom count and a licensed onsite contractor; new systems need soil morphology reports and stamped engineered drawings, with sealed plans and soil reports submitted for plan review33. Commercial/industrial facilities and subdivision developers must contact the Missouri Department of Natural Resources before seeking county approval6.

Jefferson County septic systems need inspection approval before backfill and a final inspection after backfill; alternative designs may require owner-paid special inspections3435. Only 2.3% of Jefferson County soils are rated free of severe limitations for a conventional drain field, so establish system feasibility and cost before committing to a building site15. The Missouri Department of Health and Senior Services says its application fees for onsite sewage construction are temporarily suspended effective August 28, 2026, but the county sets its own fees, so ask Code Enforcement what it charges8. Onsite sewage is for sites without central sewer; an addition, alteration or replacement permit generally cannot be issued when centralized sewer is available within 400 feet unless Code Enforcement grants a written exception supported by a reason and two detailed bids showing connection costs at least twice the onsite-system cost; the county application asks whether public sewer is available and which sewer district serves the parcel3637.

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

An RV generally may not be used as a residence in unincorporated Jefferson County unless another county ordinance provides otherwise20. An RV may be placed under a permit in an authorized RV park, and an RV may be occupied temporarily while a principal dwelling is under construction in a residential zoning district; that construction use ends when the dwelling receives its occupancy permit20. Applicable sewer, water, electrical and other county permits still apply20. We could not confirm a broader temporary-camping rule, so ask Planning before staying on vacant land.

We could not confirm a separate tiny-home category or minimum dwelling size in unincorporated Jefferson County; ask Planning and Code Enforcement how your proposed home would be classified. A tiny home intended as a dwelling must still satisfy the parcel's zoning, setbacks, building permit and sanitation requirements112438. A permanent accessory dwelling is expressly allowed in residential zoning districts subject to its permit, utility, setback, parking and ownership conditions30.

Building a home in Jefferson County: what are the steps, in order?

  1. Ask the Planning Division to confirm the parcel's zoning district, allowed use and setbacks124.
  2. Determine whether the site is in a special flood hazard area; each proposed structure or other development there requires a separate floodplain development permit3940.
  3. Establish sewer availability or septic feasibility before fixing the house site; central sewer within 400 feet generally blocks an onsite-system addition, alteration or replacement permit unless the documented exception is granted3637.
  4. Obtain a county driveway permit for work on county right-of-way or a MoDOT permit for access on state right-of-way171918.
  5. Register in the Citizen Portal and submit the building application and related plans and approvals910.
  6. Pay the applicable published fees, then schedule required building and septic inspections and obtain final approvals before backfilling the septic system or occupying the structure2422343526.

What should you check before you buy land in Jefferson County?

Start with the exact zoning district, setbacks and legal-lot status; unincorporated parcels are subject to district controls, and preliminary subdivision plats require a completed checklist and a Planning and Zoning Commission hearing1244142. A residential driveway on Jefferson County right-of-way needs a county permit with $500 refundable escrow; state right-of-way access requires a MoDOT permit17194318. Jefferson County floodplain approval covers construction and manufactured-home placement in special flood hazard areas, with a separate permit for each structure or development3940.

Resolve wastewater before selecting the house site because only 2.3% of Jefferson County soils are rated free of severe limitations for a conventional drain field15. Terrain adds cost: 77.5% of the county is wooded, and 42.5% of its land has slopes of 15% or less4445. The effective property-tax rate is about 0.8%, and the median annual bill is $1,8354647.

Watch-outs

  • Jefferson County adopted a new master plan on November 10, 2025 and is rewriting its zoning code (the Unified Development Ordinance) to match it, so confirm the current rules with the Planning Division before you rely on them48.
  • A centralized sewer available within 400 feet generally prevents an onsite-system addition, alteration or replacement permit unless Code Enforcement grants the documented exception3637.
  • Construction and other development in a Jefferson County special flood hazard area require a separate floodplain development permit3940.
  • A Jefferson County structure cannot be occupied until its final inspection is approved26.
  • A Jefferson County homeowner permit is conditional and does not waive plans, fees, inspections or trade requirements; septic applications require a licensed onsite contractor2549.

Sources

  1. Code Enforcement — Permits FAQs, quoted and re-checked
  2. Codes & Ordinances, quoted and re-checked
  3. jeffcomo.gov, quoted and re-checked
  4. jeffcomo.gov, quoted and re-checked
  5. Jefferson County Code Enforcement Division (jeffcomo.gov)
  6. Chapter 705, Article I — On-Site Sewage Treatment Code, quoted and re-checked
  7. Development Review, quoted and re-checked
  8. Missouri Department of Health and Senior Services, Onsite Wastewater Treatment Program (health.mo.gov)
  9. Permits, quoted and re-checked
  10. Permits, quoted and re-checked
  11. Chapter 500, Article I — Building Code Administration, quoted and re-checked
  12. Chapter 400 Unified Development Order, quoted and re-checked
  13. jeffcomo.gov, quoted and re-checked
  14. Codes & Ordinances, quoted and re-checked
  15. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  16. Jefferson County Code Enforcement Division (Permit FAQs) (jeffcomo.gov)
  17. Permits, quoted and re-checked
  18. Permits | Missouri Department of Transportation (Missouri statewide rule), quoted and re-checked
  19. Driveway Permit, quoted and re-checked
  20. International Residential Code 2015 Amendments — Recreational Vehicles, quoted and re-checked
  21. Jefferson County Code Enforcement Division (Codes & Ordinances) (jeffcomo.gov)
  22. Inspections, quoted and re-checked
  23. Inspections, quoted and re-checked
  24. Codes & Ordinances, quoted and re-checked
  25. ecode360.com, quoted and re-checked
  26. Jefferson County Code Enforcement Division (Building Permit Application) (jeffcomo.gov)
  27. Hillsboro: Hillsboro Building Code Amendments (Jefferson County), quoted and re-checked
  28. Crystal City: Crystal City Code § 64-2, Definitions (Jefferson County), quoted and re-checked
  29. Hillsboro: Hillsboro Zoning Code, R-1 Use Regulations (Jefferson County), quoted and re-checked
  30. UDO Section 400.2770 — Accessory Uses, Buildings and Structures, quoted and re-checked
  31. Division 3: Permitted Uses and Related Standards, quoted and re-checked
  32. Chapter 705, Article I — On-Site Sewage Treatment Code, quoted and re-checked
  33. On-Site Sewage Treatment System Permit Application, quoted and re-checked
  34. Chapter 705, Article I — On-Site Sewage Treatment Code, quoted and re-checked
  35. On-Site Sewage Treatment System Permit Application, quoted and re-checked
  36. Article I: Administration — On-Site Sewage Treatment Code, quoted and re-checked
  37. Chapter 705, Article I — On-Site Sewage Treatment Code, quoted and re-checked
  38. Article I: Administration — On-Site Sewage Treatment Code, quoted and re-checked
  39. Chapter 405 Flood Damage Prevention, quoted and re-checked
  40. Exhibit A — Jefferson County 2025 Flood Damage Prevention Ordinance, quoted and re-checked
  41. Chapter 400 Unified Development Order, quoted and re-checked
  42. Development Review, quoted and re-checked
  43. Codes & Ordinances, quoted and re-checked
  44. Wooded share of land: Bolthole Index county data
  45. Share of land at 15% slope or less: Bolthole Index county data
  46. Effective property tax rate: Bolthole Index county data
  47. Median property tax bill: Bolthole Index county data
  48. Jefferson County Planning Division (Unified Development Order) (jeffcomo.gov)
  49. Jefferson County Code Enforcement Division (On-Site Sewage Treatment System Permits) (jeffcomo.gov)

Written October 13, 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.

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Compared with neighboring counties

Like 5 of its 6 neighbors, Jefferson County requires a building permit for a home.

RuleJefferson CountySt. Louis CountyFranklin CountySt. Louis CityWashington CountySt. Charles CountySt. Francois County
Building permitRequiredRequiredRequiredRequiredNot requiredRequiredRequired
County zoningYesYesYesYesNoYesNot published
Septic permitsCounty Code Enforcement Div.County Dept. of Public HealthFranklin CountyMO Dept. of Health & Senior ServicesCounty Health Dept.County Div. of Building & Code EnforcementCounty Health Center

County locator

Jefferson County in Missouri

52
County map
Jefferson County highlighted among the Missouri counties · colored by Index score

How Jefferson County scores

Seclusion27100% ev.
Self-Sufficiency59100% ev.
Admin Boringness4690% ev.
Durability58100% ev.
Property Autonomy47100% ev.
Carry Cost73100% ev.

Evidence strength: 98%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$298kTypical home
0.8%Property tax
$5,915Land / acre
43.8"Annual rain
4.3% of yrsSevere drought
15.7 / yr (+13.4)Mid-century 100°F days
15.7 daysMid-century dry spell
2.01" (+8.9%)Mid-century 1-day rain
1.86×Wildfire change factor
100%Forward climate coverage
$1,968Home insurance / yr
1.1% / yrInsurance growth
1.38%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
131,039People within 30 min
3,461,756People within 2 hr
128,791Radius comparison (15 mi)
352.2People / sq mi
0.3%Federal land
42.5%Land at 15% slope or less
2.3%Soils rated "not limited" for septic (strict USDA rating)
9,086 acWorkable land screen
77.5%Wooded land
47.2 tonsBiomass / forest ac
56.1°FAvg temp

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Cities and towns in Jefferson County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Not yet researched: Village of Cedar Hill Lakes · Village of Lake Tekakwitha · Olympian Village · Village of Parkdale · Village of Peaceful Village · Town of Scotsdale

Answers from the rulebook for Jefferson County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

Jefferson County rules

  • Building permitRequired

    Construction requiring a building permit under Jefferson County Code Enforcement.

    • The county FAQ lists exceptions including certain decks, fences, detached accessory structures up to 200 square feet, finish work, certain pools, retaining walls, sidewalks and driveways, playground equipment, water tanks, window awnings, and ordinary repairs.
    • Emergency repairs must be submitted by the next working business day.
    • Work affecting structural elements, egress, or public health and safety is not ordinary repair.
    “You need to obtain a building permit for many reasons. A building permit ensures that your structure is in compliance with the building code and meets the minimum building standard.”
  • Owner-builder exemptionConditional

    Owner or immediate-family homeowner permits for detached single-family dwellings and accessory structures.

    • The dwelling must be used solely for living purposes.
    • The dwelling must be occupied by, or intended for immediate occupancy by, the owner and family and no other persons.
    • The permittee must personally perform all required work.
    • Only one permit may be open at a time.
    • Electrical, plumbing, and drainlaying requirements, construction documents, fees, and inspections are not waived.
    • A qualifying homeowner must pass a written test with a score of at least 75%; the permit may be revoked for improper work or noncompliance.
    • The permit is valid for one year.

    homeowner examination passing score: >= 75 percent · homeowner permit validity: 1 year

    “A permit shall be permitted to be issued for an addition, construction, repair, modification or reconstruction of an electrical, plumbing, mechanical or drainlaying system on the premises of a detached single-family dwelling, including accessory structures, to the owner or to a member of the owner's immediate family residing with him under the following conditions:”
  • Building code adoptedAdopted

    Jefferson County adopted building and related construction codes administered under county code enforcement.

    • The county page lists the 2015 International Building Code and 2015 International Residential Code, among other adopted codes.
    • The county page also lists local amendments in Chapter 500.
    “The following Codes have been adopted by Jefferson County:”
    One more reviewed finding on this topic
    • Adopted (with conditions) — County building regulation under Chapter 500.
      “Accordingly, the following technical codes, one (1) copy of which is on file in the Department of the County Clerk, are adopted and incorporated in this Article by reference as if fully set forth, except as they may be amended by other provisions of this Chapter:”
  • InspectionsRequired

    Permitted building construction subject to Jefferson County inspections.

    • Required inspections include site, footing/foundation, under-floor or slab, framing and mechanical/electrical/plumbing rough-in, gypsum board or lath, septic, and final inspection.
    • Requests should be made at least one business day before inspection; a re-inspection fee may be assessed for incomplete work.
    “All framing, electrical, plumbing, mechanical or drain system, or portion thereof, may not be covered, concealed, or put into use until it has been tested, inspected, and approved for use.”
    One more reviewed finding on this topic
    • Required — Permitted construction and septic work inspected by Jefferson County Code Enforcement.
      “Final Inspection - To be made after finish grading and the building is completed and ready for occupancy. Other inspections - In addition to the inspections specified above, the building official may require other inspections of any construction work to ensure compliance with the provisions of the codes.”
  • County-wide zoningPresent (with conditions)

    Zoning and land-use regulation in unincorporated Jefferson County.

    • The County maintains and implements the Unified Development Order; incorporated municipalities may administer separate local rules.
    “All parcels and lots in unincorporated Jefferson County are subject to property line setbacks.”
  • Local zoningPresent (with conditions)

    Unincorporated Jefferson County, where the County UDO and zoning districts regulate development.

    • This does not establish that the County administers incorporated-municipality ordinances.
    “The Planning and Zoning Commission holds hearings for rezoning cases, approves subdivision platting and various items related to planning and zoning in Jefferson County.”
  • Zoning districtsPublished

    Jefferson County zoning districts under Chapter 400.

    • Article V is identified as Zoning Districts and covers Sections 400.1350 through 400.1880.
    • The specific district map, district names, dimensional standards, and parcel-level district assignment were not extracted.
    “ARTICLE V Zoning Districts (Section 400.1350 – Section 400.1880)”
    One more reviewed finding on this topic
    • Published (with conditions) — Zoning districts and district-based development controls in unincorporated Jefferson County.
      “The Unified Development Order (UDO) was adopted on April 2, 2008 and has been amended from time to time.”
  • Minimum lot sizeDistrict specific (with conditions)

    Properties on which a principal use may be located in the Jefferson County zoning districts covered by Chapter 400, including residential development in unincorporated Jefferson County.

    • The property must meet or exceed the minimum lot-size requirement for its applicable zoning district.
    • PR-1, PR-2, PI, and PM use approved-plan or development-approval rules apply where the table states AP or where lot sizes are established through zoning approval.
    • The ordinance states that lot widths and setbacks may be reduced if open-space conservation and density design standards in Article VII are met.
    • The UDO is county zoning code; incorporated municipalities may have separate regulations.

    RA-5 minimum lot size: 5 acres · LR-2 minimum lot size: 2 acres · R-40 minimum lot size: 40000 square feet · R-20 minimum lot size: 20000 square feet · R-10 minimum lot size: 10000 square feet · R-7 minimum lot size: 7000 square feet · NC-1 minimum lot size: 5000 square feet · CC-2 minimum lot size: 20000 square feet · PB minimum lot size: 20000 square feet · NPI minimum lot size: 20000 square feet · PR-1 minimum lot size: AP (Per approved plan) · PR-2 minimum lot size: AP (Per approved plan) · PC minimum lot size: NA (Not applicable) · PI minimum lot size: AP (Per approved plan) · PM minimum lot size: AP (Densities and lot sizes established as part of zoning approval for each development)

    “Every property upon which a principal use may be located shall meet or exceed the following requirements for its respective zoning district:”
  • SetbacksSpecified

    All parcels and lots in unincorporated Jefferson County.

    • Setbacks are based on zone districts and lot shape.
    • The Planning Division can determine the applicable setback for a property.
    “Setbacks are based on zone districts and lot shape.”
  • Living in an RVLimited

    Use and occupancy of recreational vehicles in Jefferson County zoning and building-code jurisdiction.

    • A recreational vehicle is defined as a single-chassis vehicle of 400 square feet or less designed primarily for temporary recreational, camping, travel, or seasonal living quarters.
    • Unless otherwise provided by County ordinances, an RV may not be used as a residence.
    • An RV may be installed in an authorized RV park under a permit valid for one year; an extension or renewal may not exceed 60 days and requires written justifiable cause.
    • During construction of a principal dwelling in a residential zoning district, an RV may be used temporarily but must be vacated upon issuance of an occupancy permit for the principal dwelling.
    • Temporary use requires applicable sewer, water, electrical, and other local and County permits.

    RV park permit validity: 1 year · RV park extension or renewal: <= 60 days (Written request and justifiable cause required.) · RV size: <= 400 square feet (Measured at largest horizontal projections.)

    “Unless otherwise provided for in the Code of Ordinances of Jefferson County, Missouri, Recreational Vehicles may not be utilized as a residence.”
  • Accessory dwellingsAllowed (with conditions)

    Accessory dwelling units in residential zoning districts, including planned and non-planned residential districts and the PM Planned Mixed Use District.

    • A building permit is required.
    • The accessory dwelling unit must be a permanent structure.
    • It must connect to public water and sewer where available, or use on-site water and sewer facilities complying with County and State regulations.
    • It may not be sold separately from the entire property.
    • It must comply with the principal residential use's setbacks and provide sufficient on-site parking other than the driveway.
    • A mobile home may be used as an accessory dwelling unit only in RA-5 and LR-2 residential districts.
    “Accessory dwelling units may be constructed in a residential zoning district. This includes both planned and non-planned residential zoning districts and the "PM" Planned Mixed Use District.”
  • Who permits septicCounty

    County Code Enforcement administration of the county On-Site Sewage Treatment Code and permit application process.

    • The county code page identifies Chapter 705 as the On-Site Sewage Treatment Code.
    • The opened application identifies Jefferson County Code Enforcement as the application office.
    “On-Site Sewage Treatment System Permit Application Jefferson County Code Enforcement”
    One more reviewed finding on this topic
    • County (with conditions) — On-site sewage treatment systems on unincorporated land in Jefferson County.
      “The Code Official shall receive applications and issue permits for the installation and alteration of on-site sewage treatment systems, inspect the premises for which such permits have been issued and enforce compliance with the provisions of this code.”
  • Septic permitRequired

    New, replacement, or other on-site sewage treatment systems requiring Jefferson County approval.

    • A completed application must include bedroom count.
    • An active licensed on-site septic contractor must sign the application.
    • New systems require a soil morphology report, engineered sewer drawings with every page stamped, and licensed contractor verification.
    • Three full sets of sealed plans and soil reports must be submitted.
    • Applications undergo plan review before approval for issuance.
    “All applications and plans will go to plan review for further inspection of detail before approval will be granted for issuance.”
    One more reviewed finding on this topic
    • Required — Construction of an on-site sewage treatment system in unincorporated Jefferson County.
      “The construction of an on-site sewage treatment system shall not commence until the Code Official has issued a permit for such.”
  • Septic inspectionRequired

    On-site sewage treatment permits administered by Jefferson County.

    • The application identifies field preparation, on-site, rough-in before backfill, and final-after-backfill inspections.
    • A final inspection must be completed on every permit.
    • Failure to comply may result in utility disconnection, stoppage of work, and legal action.
    “A FINAL INSPECTION MUST BE COMPLETED ON EVERY PERMIT.”
    One more reviewed finding on this topic
  • Off-grid sanitationLimited

    On-site sanitation where central sewer is unavailable.

    • On-site sewage treatment systems are permitted where central sewer systems are not available and remain subject to county permitting, inspection, design, installation, and maintenance requirements.
    “On-site sewage treatment systems are permitted where central sewer systems are not available.”
  • Mandatory utility hookupConditional

    Wastewater utility connection versus on-site sewage treatment.

    • On-site sewage is allowed where central sewer is unavailable.
    • An addition, alteration, or replacement permit may not be issued when centralized sewer is available within 400 feet unless the owner submits a written exception request with a reason and two detailed cost-comparison bids showing at least twice the on-site system cost.
    • The County application asks whether public sewer is available and identifies the public sewer name if applicable.

    centralized sewer distance trigger: <= 400 feet (Written exception process applies.)

    “An addition, alteration or replacement construction permit shall not be issued if a public or private centralized sewer is available for connection within four hundred (400) feet of the parcel of land requesting the permit.”
    One more reviewed finding on this topic
    • Conditional — On-site sewage use and public-sewer connection for unincorporated property.
      “An addition, alteration or replacement construction permit shall not be issued if a public or private centralized sewer is available for connection within four hundred (400) feet of the parcel of land requesting the permit.”
  • Subdividing landRegulated (with conditions)

    Subdivision regulation under Jefferson County's Unified Development Order.

    • The official Chapter 400 index identifies an Article XVI Subdivisions.
    • Specific subdivision thresholds and application requirements were not extracted.
    “ARTICLE XVI Subdivisions (Section 400.5010 – Section 400.5690)”
    One more reviewed finding on this topic
    • Regulated (with conditions) — Subdivision platting and preliminary-plat review in Jefferson County.
      “All preliminary plat reviews are heard before the Planning and Zoning Commission. Each request must be accompanied by a completed checklist.”
  • Driveway accessRequired

    Private or commercial driveways constructed on Jefferson County rights-of-way.

    • The source applies specifically to Jefferson County right-of-way.
    • The permit escrow fee is $500 and is fully refundable upon satisfactory completion according to the county permits page.
    • The separate application identifies residential, agricultural, subdivision, and commercial/industrial escrow amounts and permit conditions.

    permit escrow fee: 500 USD (county permits page states fully refundable upon satisfactory completion)

    “Any person wanting to construct a private or commercial driveway on Jefferson County right-of-way must have a Driveway Permit. The permit escrow fee is $500 and is fully refundable upon satisfactory completion of the driveway.”
    One more reviewed finding on this topic
    • Required — Private or commercial driveways constructed on Jefferson County right-of-way.
      “Any person wanting to construct a private or commercial driveway on Jefferson County right-of-way must have a Driveway Permit.”
  • Building in a floodplainRequired

    Construction and other development in Jefferson County special flood hazard areas identified by the county's flood maps.

    • The chapter applies to numbered and unnumbered A zones and AE, AO, and AH zones on FIRM panels 29099CIND1C and 29099CIND2C dated October 2, 2025, as amended, and future revisions.
    • A separate floodplain development permit is required for each structure or other development.
    • Applications must identify the property, work, occupancy, values, flood elevations, plans, signatures, professional engineer or surveyor, and required local, state, and federal permits.

    FIRM panel date: October 2, 2025 (as amended and future revisions)

    “A floodplain development permit shall be required for all proposed construction or other development, including the placement of manufactured homes, in the areas described in Section 405.040(A).”
    One more reviewed finding on this topic
    • Required — Proposed construction or other development, including manufactured-home placement, in Jefferson County special flood hazard areas identified in Section 405.040(A).
      “A floodplain development permit shall be required for all proposed construction or other development, including the placement of manufactured homes”
  • Permit feesPublished (with conditions)

    County building-permit fee schedule and related permit fees.

    • The county states that Ordinance 21-0356 adopted a new fee schedule for all building permits.
    • The county states the fee schedule is effective for all permits starting September 6, 2021.
    • The driveway permit source separately states escrow amounts of $500 residential, $500 agricultural, $1,000 subdivision, and $1,500 commercial/industrial.

    driveway residential escrow: 500 USD (Collected prior to issuing permit.) · driveway agricultural escrow: 500 USD (Collected prior to issuing permit.) · driveway subdivision escrow: 1000 USD (Collected prior to issuing permit.) · driveway commercial/industrial escrow: 1500 USD (Collected prior to issuing permit.)

    “The new fee schedule is in effect for ALL PERMITS STARTING ON SEPTEMBER 6, 2021.”
    One more reviewed finding on this topic
    • Published (with conditions) — County building-permit fees and related permit fees.
      “On July 26, 2021 the Jefferson County, Missouri Council adopted Ordinance Number 21-0356 amending the Building Code and adopting a new fee schedule to apply to all building permits. The new fee schedule is in effect for ALL PERMITS STARTING ON SEPTEMBER 6, 2021.”
  • Permit processPublished (with conditions)

    County building-permit application, payment, inspection scheduling, and status tracking.

    • Applicants must register online before using the Citizen Portal.
    • The portal supports applying for permits and licenses, scheduling inspections, and checking application status.
    • Questions may be directed to Code Enforcement at 636-797-5310.
    • The county states that the fee schedule applies to all permits.
    “Once registered, you can then apply for permits and licenses, schedule inspections and check the status of your applications.”
    One more reviewed finding on this topic
    • Published (with conditions) — Building permits and inspections submitted through Jefferson County's Citizen Portal.
      “Customers will need to register online before being able to use the Citizen Portal. Once registered, you can then apply for permits and licenses, schedule inspections and check the status of your applications.”

Missouri rules that apply here

  • Well permitLimited

    Construction or alteration of a public well serving a Missouri public water system.

    • Public water systems must receive written approval from the Missouri Department of Natural Resources Public Drinking Water Branch before constructing or altering a public well.
    • The requirement does not apply when the system meets the charitable-and-benevolent-organization exemptions in section 640.116, RSMo.
    • Anyone proposing to install a public well must contact the department’s regional office for a well-site survey.
    • The survey addresses minimum isolation or setback distances from known or potential contaminant sources, including septic tanks, sanitary sewer lines, and landfills.
    • Before applying for construction authorization, the public water system must obtain an estimated casing-depth letter from the Missouri Geological Survey Water Resources Center.
    • There is no fee for the well-site-survey and estimated-casing-depth-letter services.
    • Failure to obtain construction authorization may result in approval delays and possibly require the owner to properly plug the well and drill a new one according to 10 CSR 60-3.

    public water system threshold: at least 15 service connections or regularly serves an average of at least 25 individuals daily, at least 60 days per calendar year

    “Public water systems must receive written approval from the PDWB before constructing or altering a public well”
    2 more reviewed findings on this topic
    • Required — A person or contractor conducting regulated work to drill, construct, repair, reconstruct, plug, or install pumps or pumping equipment in a water well, heat-pump well, monitoring well, or related well in Missouri.
      “A non-restricted permit is required to drill, construct, repair, reconstruct, plug, or install pumps or pumping equipment in a well.”
    • Limited — Construction or repair of water wells, installation or replacement of pumps, and associated plumbing and electrical work in Missouri.
      “A non-restricted water well installation permit is required to construct or repair a water well in Missouri.”
  • Agricultural exemptionAvailable (with conditions)

    Farm buildings and farm structures used for agricultural purposes under the county building and land-use restriction provisions of RSMo sections 64.800 to 64.905.

    • The exemption does not apply within incorporated portions of counties.
    • The exemption applies to raising crops, livestock, orchards, or forestry and to specified rice-farming or flood-irrigation impoundments.
    • For farm buildings or farm structures, the area must not be within the area shown on the flood hazard area map.
    • The statute preserves the validity of county ordinances or orders adopted before March 4, 1991.
    • Other laws and local requirements may still apply.

    rice-farming or flood-irrigation berm height: <= 18 inches (small berms placed around a field to hold water for growing rice or flood irrigation)

    “This section shall not apply to the erection, maintenance, repair, alteration or extension of farm buildings or farm structures used for such purposes in an area not within the area shown on the flood hazard area map.”
    4 more reviewed findings on this topic
    • Available (with conditions) — Erection, maintenance, repair, alteration, or extension of farm buildings or farm structures as against county fire-protection or fire-prevention ordinances.
      “Notwithstanding any provision of law to the contrary, no fire protection or fire prevention ordinance adopted by any county in this state shall be exercised so as to impose regulations or to require permits with respect to the erection, maintenance, repair, alteration, or extension of farm buildings or farm structures.”
    • Available (with conditions) — Erection, maintenance, repair, alteration, or extension of farm buildings or farm structures used for agricultural purposes under RSMo section 64.890, outside incorporated portions of counties and outside areas shown on flood hazard area maps.
      “This section shall not apply to the erection, maintenance, repair, alteration or extension of farm buildings or farm structures used for such purposes [...]”
    • Available (with conditions) — Farm buildings and farm structures statewide, with respect to county fire-protection and fire-prevention ordinances.
      “no fire protection or fire prevention ordinance adopted by any county in this state shall be exercised so as to impose regulations or to require permits [...]”
    • Available — Erection, maintenance, repair, alteration, or extension of farm buildings or farm structures with respect to county fire-protection or fire-prevention ordinances.
      “Notwithstanding any provision of law to the contrary, no fire protection or fire prevention ordinance adopted by any county in this state shall be exercised so as to impose regulations or to require permits with respect to the erection, maintenance, repair, alteration, or extension of farm buildings or farm structures.”
  • county zoning authorityLimited

    Missouri county zoning authority over unincorporated land.

    • RSMo § 64.850 applies to counties of the first class without a charter and counties of the second, third, or fourth class.
    • RSMo § 64.620 applies to counties of the second or third class to which §§ 64.510–64.690 apply.
    • Adoption under §§ 64.510–64.690 requires approval by vote of the people under § 64.530.
    • The authority applies in unincorporated portions and not incorporated portions.
    • The regulations must be in accordance with a comprehensive plan.
    • Under § 64.090, the zoning power does not apply to raising crops, livestock, orchards, or forestry; seasonal or temporary rice-farming or flood-irrigation impoundments; specified farm structures outside mapped flood-hazard areas; or underground mining entered through shafts outside mapped flood-hazard areas.
    • Existing lawful uses and specified public-utility services are protected under the cited statutory schemes.
    “the county commission of any county of the first class not having a charter form of government, or of any county of the second, third or fourth class may, after approval by vote of the people as provided in section 64.845, regulate and restrict, by order of record, in the unincorporated portions of the county, the height, number of stories, and size of buildings, the percentage of lots that may be occupied, the size of yards, courts and other open spaces, the density of population, the location and use of buildings, structures and land for trade, industry, residence or other purposes.”
    2 more reviewed findings on this topic
  • county building authorityLimited

    County authority to regulate residential construction and issue building permits in unincorporated areas of Missouri.

    • The authority under sections 64.170 to 64.200 applies to counties of the first and second classification.
    • A county that had not adopted a building code before August 28, 2001, must obtain voter approval before adopting one under those sections.
    • Only voters in the area affected by the proposed code may vote; incorporated-territory citizens cannot vote on a code affecting a county.
    • The county commission must hold at least three public hearings and provide the statutory newspaper publication and county posting notices before adoption.
    • Regulations adopted under section 64.180 apply to unincorporated territory, except as otherwise provided.
    • Adopted or amended codes after August 28, 2001, must use a current, calendar year 1999 or later edition of a nationally recognized building code, as amended.
    • A county building ordinance may not conflict with liquefied petroleum gas installations governed by section 323.020.

    public hearings before adoption: >= 3 hearings minimum (Section 64.180(3)) · newspaper notice: >= 15 days (Notice of hearing time and place must be published in at least two newspapers having general circulation within the county) · posted notice: >= 15 days (Notice must be posted in four conspicuous places in the county) · minimum nationally recognized building-code edition: >= calendar year 1999 edition year (Applies after August 28, 2001, under section 64.180)

    “The regulations adopted shall be applicable to the unincorporated territory of the county, except as otherwise provided herein”
    2 more reviewed findings on this topic
    • Limited — County regulation of construction and issuance of building permits for buildings, including residential construction, in Missouri counties, with the practical focus on county-controlled areas outside incorporated territory.
      “the county commission in all counties of the first and second classification [...] is for this purpose empowered [...] to adopt [...] regulations to control the construction”
    • Limited — Missouri counties' authority to require permits and regulate residential construction in unincorporated areas.
      “Before the adoption of such code of regulations, the county commission shall hold at least three public hearings thereon”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

  • Certificate of occupancy — Certificate-of-occupancy requirements for structures in unincorporated Jefferson County.
  • Minimum dwelling size — Minimum dwelling-size requirements under the County UDO and building codes.
  • Lot coverage — Lot-coverage limits under Jefferson County zoning districts.
  • Building height — Building-height limits under Jefferson County zoning districts.
  • Camping on your land — Temporary camping on private land outside an authorized recreational vehicle park or a specifically approved use.
3 more unanswered
  • Tiny homes
  • Manufactured homes
  • Short-term rentals

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Living off-grid in Jefferson County, Missouri

Is Jefferson County a good place to live off-grid or homestead?

Jefferson County scores 52/100 on the Bolthole Index, a solid county profile. Its strengths: manageable long-term carry cost and workable self-sufficiency basics: 43.8″/yr rainfall and 77.5% wooded land. Watch-outs: about 131,039 people within a 30-minute drive.

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

Jefferson County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Jefferson County Code Enforcement Division. Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

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

Living in an RV on your own land in Jefferson County is limited to specific cases: Use and occupancy of recreational vehicles in Jefferson County zoning and building-code jurisdiction. A recreational vehicle is defined as a single-chassis vehicle of 400 square feet or less designed primarily for temporary recreational, camping, travel, or seasonal living quarters. Unless otherwise provided by County ordinances, an RV may not be used as a residence. Confirm with the county before relying on it.

How much does land cost in Jefferson County, Missouri?

Land in Jefferson County runs about $5,915 per acre, based on the latest county data.

What is the water situation in Jefferson County?

Jefferson County gets about 43.8" of rain a year, with severe drought in roughly 4.3% of years.

How remote is Jefferson County?

A representative private-land location has about 131,039 people within a 30-minute drive and 3,461,756 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

How Jefferson compares in Missouri

Compare side-by-side →See all 115 Missouri counties ranked →