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§ 02
When a permit is required
Permit triggers and exempt work for Jefferson County
County FAQ states permits are required for many building, structural, trade, and safety-related projects in unincorporated Jefferson County
Decks not exceeding 200 square feet, not over 30 inches above grade, not attached to a dwelling, and not serving the required exit door
Fences not over 8 feet high
Gas or electric hot water heater replacement
One-story detached accessory structures not over 200 square feet
Painting, papering, tiling, carpeting, cabinets, countertops, and similar finish work
Prefabricated swimming pools less than 24 inches deep
Retaining walls not over 6 feet high unless supporting a surcharge
Sidewalks and driveways not more than 30 inches above adjacent grade and not over a basement or story below
Swings and playground equipment accessory to a one- or two-family dwelling
Certain tanks, awnings, minor repairs, and emergency repairs filed the next business day where applicable
- Exempt Decks not exceeding 200 square feet, not over 30 inches above grade, not attached to a dwelling, and not serving the required exit door
- Exempt Fences not over 8 feet high
- Exempt Gas or electric hot water heater replacement
- Exempt One-story detached accessory structures not over 200 square feet
- Exempt Painting, papering, tiling, carpeting, cabinets, countertops, and similar finish work
- Exempt Prefabricated swimming pools less than 24 inches deep
- Exempt Retaining walls not over 6 feet high unless supporting a surcharge
- Exempt Sidewalks and driveways not more than 30 inches above adjacent grade and not over a basement or story below
- Exempt Swings and playground equipment accessory to a one- or two-family dwelling
- Exempt Certain tanks, awnings, minor repairs, and emergency repairs filed the next business day where applicable
Required documents
- When a permit is required: County FAQ states permits are required for many building, structural, trade, and safety-related projects in unincorporated Jefferson County
- Required documents: Permit-specific plans; proof of ownership for Planning filings; site plan and checklist materials where zoning, CUP, variance, deviation, or plat review applies
- Permit validity/expiration: Not clearly posted on the reviewed public county pages
- Owner-builder rules if available: Not clearly posted on the reviewed public county pages
- Contractor license requirements: County permit page separately lists contractor licenses
- Building code adopted: Jefferson County Building Code fee ordinance and county code provisions are posted; county FAQ exemption language tracks IRC-style thresholds. Planning and floodplain controls also apply where relevant
- Building code
- Jefferson County Building Code fee ordinance and county code provisions are posted; county FAQ exemption language tracks IRC-style thresholds. Planning and floodplain controls also apply where relevant
- Permit validity
- Not clearly posted on the reviewed public county pages
- Owner-builder
- Not clearly posted on the reviewed public county pages
- Contractor requirements
- County permit page separately lists contractor licenses
§ 03
Application process
Typical processing: Not posted for county building permits; Planning advises applicants to discuss requests with staff before submittal
- 01 Confirm the parcel is in unincorporated Jefferson County and identify whether Code Enforcement, Planning, Highway/Stormwater, floodplain, or sewage review applies
- 02 For zoning and land-use filings, use the Citizen Portal and schedule any required pre-application conference with Planning at 636-797-5580
- 03 Submit permit and plan materials to the applicable county division, including any deed or proof-of-ownership and checklist items required by Planning
- 04 Pay plan review and permit fees under the county fee ordinance
- 05 Receive permit approval before work starts and coordinate inspections as work progresses
Typical processing time: Not posted for county building permits; Planning advises applicants to discuss requests with staff before submittal
Source: Jefferson County Code Enforcement Division (formerly the Building Division) ↗
§ 04
Fee schedule
Jefferson County building permit fees
Fee type
Amount
01
Minimum permit fee
Residential building and each revision submittal $40.00 plan review; commercial building submittal $200.00; processing fee $25.00
02
Plan check fee
Residential submittal $40.00; commercial submittal $200.00; sewage submittal $40.00
03
Permit fee formula
Valuation-based and square-foot-based building permit fee tables under Ordinance 21-0356; county also lists fixed review and processing fees
04
Reinspection fee
Inspection or re-inspection fee $50.00
County fee ordinance says plan review and submittal fees are paid upon application and deducted from total fee
Fees change periodically. Confirm at the official fee schedule ↗ before budgeting.
§ 05
Required inspections
Scheduling and sequence
How to schedule
- Coordinate with county Code Enforcement Division; Planning and other county divisions may require parallel signoff depending on permit type ()
- Inspection hours
- Not clearly posted on the reviewed public county pages
Typical sequence: Permit issuance, trade or structural inspections during work, then final approval; actual sequence varies by project and whether zoning, floodplain, sewage, or stormwater review applies
§ 06
Frequently asked
Common questions about unincorporated Jefferson County permits
01 Do I need a building permit in unincorporated Jefferson County, MO? ▸
County FAQ states permits are required for many building, structural, trade, and safety-related projects in unincorporated Jefferson County
02 How much does a building permit cost in unincorporated Jefferson County, MO? ▸
Building permit fees in unincorporated Jefferson County, MO are set by the local building department and vary by project type and valuation. The minimum permit fee is Residential building and each revision submittal $40.00 plan review; commercial building submittal $200.00; processing fee $25.00. Fees are calculated as: Valuation-based and square-foot-based building permit fee tables under Ordinance 21-0356; county also lists fixed review and processing fees. Plan check fee: Residential submittal $40.00; commercial submittal $200.00; sewage submittal $40.00.
03 How do I apply for a building permit in unincorporated Jefferson County, MO? ▸
To apply for a building permit in unincorporated Jefferson County, MO, follow these steps: 1. Confirm the parcel is in unincorporated Jefferson County and identify whether Code Enforcement, Planning, Highway/Stormwater, floodplain, or sewage review applies 2. For zoning and land-use filings, use the Citizen Portal and schedule any required pre-application conference with Planning at 636-797-5580 3. Submit permit and plan materials to the applicable county division, including any deed or proof-of-ownership and checklist items required by Planning 4. Pay plan review and permit fees under the county fee ordinance 5. Receive permit approval before work starts and coordinate inspections as work progresses
04 How long does it take to get a building permit in unincorporated Jefferson County, MO? ▸
Building permit processing times in unincorporated Jefferson County, MO typically run Not posted for county building permits; Planning advises applicants to discuss requests with staff before submittal. Timelines can vary based on project complexity and current department workload.
05 What work is exempt from building permits in unincorporated Jefferson County, MO? ▸
Not all construction work requires a permit in unincorporated Jefferson County, MO. The following work is generally exempt: Decks not exceeding 200 square feet, not over 30 inches above grade, not attached to a dwelling, and not serving the required exit door; Fences not over 8 feet high; Gas or electric hot water heater replacement; One-story detached accessory structures not over 200 square feet; Painting, papering, tiling, carpeting, cabinets, countertops, and similar finish work; Prefabricated swimming pools less than 24 inches deep; Retaining walls not over 6 feet high unless supporting a surcharge; Sidewalks and driveways not more than 30 inches above adjacent grade and not over a basement or story below; Swings and playground equipment accessory to a one- or two-family dwelling; Certain tanks, awnings, minor repairs, and emergency repairs filed the next business day where applicable. When in doubt, confirm with the local building department before starting work.
06 How do I schedule a building inspection in unincorporated Jefferson County, MO? ▸
Once your permit is issued and work reaches an inspection milestone, you can schedule a building inspection in unincorporated Jefferson County, MO via: Coordinate with county Code Enforcement Division; Planning and other county divisions may require parallel signoff depending on permit type.
last verified April 2026
source Jefferson County Code Enforcement Division (formerly the Building Division) ↗
entry id permits/missouri/jefferson/unincorporated
Educational reference. Permit rules and fees change — confirm current requirements directly with Jefferson County Code Enforcement Division (formerly the Building Division) before applying. Jaspector is not legal advice.