Bolthole Index

Jefferson County, Missouri

Building permits, zoning and septic rules in Festus, Missouri

Festus, Missouri requires building permits for substantial improvements and work involving framing, plumbing or electrical installation or replacement.1 Festus handles city building permits and zoning; the Building Official also issues written private sewage disposal permits.23 For land outside Festus in Jefferson County, use the Jefferson County guide for the county’s unincorporated-area zoning rules.4

At a glance

Building permits
City approval for substantial improvements and framing, plumbing or electrical work1
Zoning
Festus districts include Non-Urban and Single-Family Dwelling districts5
Septic permits
Written permit from the Festus Building Official; confirm additional state approval36
Non-Urban lots
N-1: minimum 5 acres and 150 feet wide, subject to code exceptions7
Single-family lots
E-1: minimum 1 acre and 150 feet wide, subject to code exceptions8
Building codes
2021 International Residential Code with city amendments and specified appendices9

Who to call

Building permits

Festus Building and Planning Department

City building permits, plan review, inspections, zoning and floodplain management

636-937-6646

950 N 5th Street Festus MO 63028

Codes & inspections

Festus Building and Planning Department — Residential Building Permit Requirements

Residential building applications, drawings and land disturbance requirements

636-937-6646

Septic permits

Festus Building Official — Private Sewage Disposal

City private sewage disposal permit applications and inspections

Health department

Missouri DHSS Onsite Wastewater Treatment Program

State wastewater permitting guidance and incorporated-area authority questions

[email protected]

Contact details are copied from each office’s official page and were checked against it on October 12, 2026.

Off-grid gear

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

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Do you need a building permit in Festus, MO?

Festus requires a building permit for a substantial improvement, with the building commissioner or authorized agent deciding whether a project meets that description.1 Replacement or installation of framing, plumbing or electrical also requires approval.1 New construction and major renovation normally require drawings sealed by an architect or engineer.1 Festus has adopted the 2021 International Residential Code with city amendments and specified appendices, so ask the city to identify the applicable requirements before commissioning plans.9

Who issues building permits and handles zoning in Festus?

The Festus Building and Planning Department handles residential, commercial and industrial building permits, construction plan review and inspections.2 Call 636-937-6646 or visit 950 N 5th Street Festus MO 63028 to discuss a city project.2 The same department assists with city zoning ordinances and floodplain management.2 Start with that city counter for a Festus address; Jefferson County’s zoning and property-line setback rules apply to unincorporated county land.24

Does Festus have zoning, minimum lot sizes and setbacks?

Festus zoning includes the N-1 Non-Urban and E-1 Single-Family Dwelling districts, among other districts; identify the parcel’s district before using any dimensional rule.5 In N-1, minimum lot area is 5 acres and minimum width is 150 feet, subject to the code’s dimensional exceptions.7 In E-1, the corresponding minimums are 1 acre and 150 feet, with the same exception qualification.8 N-1 minimum yards are 30 feet front, 25 feet on each side and 40 feet rear; E-1 minimum yards are 50 feet front, 15 feet on each side and 30 feet rear, subject to the stated code exceptions.1011

How do septic permits work inside Festus?

Before construction of a private sewage disposal system in Festus, obtain a written permit signed by the city Building Official.3 Apply on the city’s form with the plans, specifications and other information the Building Official requires; the city code states a $50 permit and inspection fee.1213 Installation must satisfy the Building Official before the permit becomes effective.3 Ask the city and Missouri DHSS which additional wastewater approval applies to the address: DHSS warns that some incorporated areas fall outside county wastewater permitting authority.14 Missouri’s temporary suspension of state wastewater application fees does not establish that Festus’s separate city fee has disappeared.1513

Can you live in an RV or tiny home in Festus?

We could not confirm a general rule allowing RV occupancy, temporary camping or tiny-home occupancy on private land inside Festus; ask the Festus Building and Planning Department about the proposed use before buying a vehicle or designing a home.2 Ask the department to distinguish a dwelling from an accessory structure and to identify the parcel’s zoning district.2 Festus publishes district regulations and adopts residential building standards, so the district and construction requirements both need attention in a small-home proposal.59 We could not confirm a city owner-builder exemption or minimum dwelling floor area; include those questions in the same discussion.2

Building a home in Festus: what should you do first?

Start by asking Festus Building and Planning to identify the zoning district and review the intended use and layout.2 Allow for the applicable district’s lot dimensions and yards before positioning the house.781011 Next, submit the completed building application, 2 sets of construction drawings and a site plan to Festus Public Works; new construction normally needs sealed drawings.1 Ask about land disturbance approval before disrupting soil.1 Resolve private sewage disposal approval before system construction and arrange its final inspection with the Building Official.3 For mapped floodplain development, ask the city about floodplain approval; Missouri requires a permit for all floodplain development.216

Watch-outs

  • We could not confirm Festus’s general building inspection schedule or occupancy approval requirements; ask Building and Planning before scheduling work or moving in.2
  • County agricultural land-use exemptions under the cited Missouri statute exclude incorporated territory, so do not use that exemption as a Festus construction waiver.17
  • Jefferson County’s soil figures are countywide: only 2.3% of soils are rated not limited for conventional septic drain fields, which supports arranging a site evaluation rather than assuming septic is impossible.18

Sources

  1. Festus Building and Planning Department — Residential Building Permit Requirements (festusmo.gov)
  2. Festus Building and Planning Department (festusmo.gov)
  3. Festus Building Official — Private Sewage Disposal (ecode360.com)
  4. jeffcomo.gov, quoted and re-checked
  5. Chapter 405, Article II District Regulations (Festus), quoted and re-checked
  6. OWTS Construction Permit Process (Missouri statewide rule), quoted and re-checked
  7. Chapter 405, Article II District Regulations (Festus), quoted and re-checked
  8. Chapter 405, Article II District Regulations (Festus), quoted and re-checked
  9. Chapter 500, Article I Building Code (Festus), quoted and re-checked
  10. Chapter 405, Article II District Regulations (Festus), quoted and re-checked
  11. Chapter 405, Article II District Regulations (Festus), quoted and re-checked
  12. ecode360.com (Festus), quoted and re-checked
  13. ecode360.com (Festus), quoted and re-checked
  14. Missouri DHSS Onsite Wastewater Treatment Program (health.mo.gov)
  15. OWTS Construction Permit Process (Missouri statewide rule), quoted and re-checked
  16. Floodplain Forms (Missouri statewide rule), quoted and re-checked
  17. RSMo Section 64.890 (Missouri statewide rule), quoted and re-checked
  18. 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

Written October 12, 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.

Answers from the rulebook for Festus

Festus’s own rules

  • Building code adoptedAdopted

    Building construction inside Festus city limits.

    • The City adopts the listed technical codes by reference.
    • Only the appendices specifically listed in Section 500.010 are adopted.
    • Section 500.015 contains City amendments; the cited update ordinance is dated August 26, 2024.

    International Building Code: 2021 (Appendices B, E, and K listed) · International Residential Code: 2021 (Appendices AE, AH, and AV listed) · International Private Sewage Disposal Code: 2021 · National Electric Code: 2020

    “Accordingly, the following technical codes, one (1) copy of which is on file in the office of the City Clerk, are adopted and incorporated in this Article by reference as if fully set forth, except as they may be amended by Section 500.015 or other provisions of this Chapter:”
  • Zoning districtsPublished

    Zoning districts inside Festus city limits.

    • The opened Article II identifies N-1, E-1, E-2, R-1, R-2, R-3, R-4, B-1, B-2, B-3, B-4, and I-1 districts.
    “Section 405.290 District "N-1" Non-Urban District. Section 405.300 District "E-1" Single-Family Dwelling District. Section 405.310 District "E-2" Clustered Home Single-Family Dwelling District. Section 405.320 District "R-1" Single-Family Dwelling District.”
  • Permit feesPublished (with conditions)

    Private sewage disposal permits inside Festus city limits.

    • The fee is stated for the private sewage disposal permit and inspection process, not necessarily for general building permits.

    permit and inspection fee: 50 USD

    “A permit and inspection fee of fifty dollars ($50.00) shall be paid to the City at the time the application is filed.”
  • Permit processPartial

    Private sewage disposal and subdivision processes inside Festus city limits.

    • Private sewage disposal requires a written Building Official permit, supporting plans/specifications, a $50 fee, and final inspection.
    • Subdivision regulations identify minor and major subdivision procedures and plat requirements.
    “The application for such permit shall be made on a form furnished by the City, which the applicant shall supplement by any plans, specifications and other information as are deemed necessary by the Building Official.”

Rules another office applies inside Festus

Festus does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

  • Minimum lot sizeSpecified

    E-1 Single-Family Dwelling District inside Festus city limits.

    • The table applies except as provided in Section 405.690.

    lot area: >= 1 acre (except as provided in Section 405.690) · lot width: >= 150 feet (except as provided in Section 405.690)

    “The following minimum dimensional requirements shall apply except as provided in Section 405.690:”
    One more reviewed finding on this topic
  • SetbacksSpecified

    E-1 Single-Family Dwelling District inside Festus city limits.

    • The table applies except as provided in Section 405.690.

    front yard depth: >= 50 feet (except as provided in Section 405.690) · side yard width each: >= 15 feet (except as provided in Section 405.690) · rear yard depth: >= 30 feet (except as provided in Section 405.690)

    “The following minimum dimensional requirements shall apply except as provided in Section 405.690:”
    One more reviewed finding on this topic
  • Building heightSpecified

    E-1 Single-Family Dwelling District inside Festus city limits.

    • Section 405.680 provides exceptions.

    principal and conditional uses: <= 30 feet maximum (two and one-half stories or thirty feet, whichever is less) · accessory uses: <= 15 feet maximum (one story or fifteen feet, whichever is less)

    “Principal and conditional uses: Two and one-half (2½) stories or thirty (30) feet, whichever is less;”
    One more reviewed finding on this topic
    • Specified — N-1 Non-Urban District inside Festus city limits.
      “Principal and conditional uses: Two and one-half (2½) stories or thirty (30) feet, whichever is less;”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Festus or Jefferson County directly.

  • Building permit — General building permits inside Festus city limits.
  • Owner-builder exemption — Owner-builders inside Festus city limits.
  • Inspections — General building inspections inside Festus city limits.
  • Certificate of occupancy — Certificates of occupancy inside Festus city limits.
  • Minimum dwelling size — Single-family dwellings inside Festus city limits.
10 more unanswered
  • Lot coverage
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Well permit
  • Agricultural exemption
  • Driveway access
  • 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.

Unanswered questions are usually a sign that Festus publishes no rule on the point, not that none exists. Jefferson County’s page lists the county offices to call.

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