Bolthole Index

St. Louis County, Missouri

Building permits, zoning and septic rules in Des Peres, Missouri

The City of Des Peres, Missouri, in St. Louis County, sets its own zoning through Appendix C of its code1 and reviews residential building permits through its Public Works office, with normal review of 7-10 business days2. Septic permits for St. Louis County are handled by the county health department, not the city3.

At a glance

Building permit
City residential building permit, reviewed by Des Peres Public Works42
Zoning
City zoning districts under Appendix C of the city code15
Building code
2018 International codes with local amendments6
Plan review time
7-10 business days, no expedited review2
Permit fees
$100 plan review plus $6 per $1,000 of construction cost4
Septic
St. Louis County Department of Public Health (confirm for your address)3
Wells
State water-well installation permit required7
Floodplain
Separate city floodplain development permit8

Who to call

Building permits

City of Des Peres Public Works (building permits)

Residential and commercial building permits, land management permits, inspections scheduling and zoning petitions inside Des Peres

314-835-6100

permits@desperesmo.org

12325 Manchester Road, Des Peres, MO 63131

Zoning

City of Des Peres zoning districts and Appendix C

Zoning district list, zoning map and Appendix C zoning regulations for Des Peres

Building permits

St. Louis County Department of Public Works (mechanical, electrical and plumbing permits)

Mechanical, electrical and plumbing permits that Des Peres applicants obtain from the county before construction

Septic permits

St. Louis County Department of Public Health

Septic (onsite wastewater) permitting for St. Louis County

314-615-0600

administration.doh@stlouisco.com

6121 North Hanley Road, Berkeley, MO 63134

Contact details are copied from each office’s official page and were checked against it on October 24, 2026.

Off-grid gear

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

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Does Des Peres, Missouri have zoning, and what does it mean for RVs, tiny homes and setbacks?

Des Peres has its own zoning. The city publishes a list of zoning districts and a zoning map, and directs users to Appendix C, Zoning District Regulations, for the full code159. Lot size, setbacks and which uses are allowed depend on the district your parcel sits in, so look up the district first.

We could not confirm Des Peres rules on RV occupancy, tiny homes, accessory dwellings or minimum dwelling size. Ask Des Peres Public Works at permits@desperesmo.org, and request a zoning verification letter for the address before you commit to a purchase10.

Do you need a building permit in Des Peres, and who issues it?

Des Peres issues its own building permits. The city adopted the 2018 International Building, Residential, Swimming Pool and Spa, Existing Building, Fire and Property Maintenance Codes with local amendments as its building code6. The city's Public Works office takes residential building permit applications10.

Mechanical, electrical and plumbing permits for Des Peres projects come separately from the St. Louis County Department of Public Works, before construction starts11. The city also treats subdivision as a regulated petition12, and development in a floodplain needs its own city floodplain permit8.

What does a Des Peres residential building permit cost and how long does review take?

A Des Peres residential building permit carries a $100 plan review fee due at submittal and a permit fee of $6 per $1,000 of construction cost, collected when the permit is picked up4. The residential form also requires a refundable escrow deposit; we could not confirm the amount, so ask Public Works4.

Normal review takes 7-10 business days, and the city offers no expedited review210. Inspections must be scheduled at least 24 hours ahead by email to the Building/Public Works Department13.

How do septic permits work inside Des Peres?

Septic permits are not issued by the City of Des Peres. In St. Louis County, onsite wastewater permitting runs through the county, and Missouri's health department lists both the St. Louis County plumbing department and the St. Louis County Department of Public Health as ordinance authorities3. Missouri requires a permit to install or repair most onsite wastewater systems14.

Whether a given Des Peres address is on public sewer or needs a septic system is not something we could confirm. Call the St. Louis County Department of Public Health at 314-615-0600 before you assume either15. Wells follow state rules: a water-well installation permit is required to construct or repair a well7.

Building a home in Des Peres: the steps, in order

  1. Find the parcel's zoning district on the city zoning map and read that district in Appendix C59.
  2. Ask Public Works for a zoning verification letter if the use is not clear10.
  3. Submit the residential building permit application with a site plan, construction documents and the plan review fee4.
  4. Allow normal review time, then pick up the permit and pay the permit fee2.
  5. Get mechanical, electrical and plumbing permits from St. Louis County Public Works before work starts11.
  6. Email Public Works to schedule each inspection1310.

What stays with St. Louis County, and what to check before you buy in Des Peres

Septic permitting and the county health department stay with St. Louis County3. Outside city limits, unincorporated land follows the county's own rules instead; see the St. Louis County page for those answers.

Before buying, check the floodplain status of the lot, since new or substantially improved residential buildings in a floodplain must have the lowest floor one foot above base flood elevation8. St. Louis County's effective property tax rate is 1.2%16, and the median tax bill is $3,193 a year17.

Watch-outs

  • The residential permit form also says deed restrictions and subdivision indentures are not reviewed or enforced by the city, so read the deed and plat before you build10.
  • We could not confirm Des Peres rules on RVs, tiny homes, accessory dwellings or minimum home size; ask Des Peres Public Works at permits@desperesmo.org10.
  • Septic and well rules come from St. Louis County and the state, not the city, and we could not confirm sewer availability for any specific address3.

Sources

  1. Zoning Districts | Des Peres, MO - Official Website (Des Peres), quoted and re-checked
  2. Permit Requirements, Forms and Inspections | Des Peres, MO - Official Website (Des Peres), quoted and re-checked
  3. OWTS Construction Permit Process — St. Louis County authorities, quoted and re-checked
  4. Residential Building Permit (Des Peres), quoted and re-checked
  5. Zoning Districts | Des Peres, MO - Official Website (Des Peres), quoted and re-checked
  6. Ordinance No. 2873 — Adoption of Building Codes 2018 (Des Peres), quoted and re-checked
  7. Water Wells - PUB2945, quoted and re-checked
  8. City of Des Peres Floodplain Development Permit/Application (Des Peres), quoted and re-checked
  9. City of Des Peres zoning districts and Appendix C (desperesmo.org)
  10. City of Des Peres Public Works (building permits) (desperesmo.org)
  11. St. Louis County Department of Public Works (mechanical, electrical and plumbing permits) (desperesmo.org)
  12. Permit Requirements, Forms and Inspections | Des Peres, MO - Official Website (Des Peres), quoted and re-checked
  13. Residential Building Permit (Des Peres), quoted and re-checked
  14. OWTS Construction Permit Process (Missouri statewide rule), quoted and re-checked
  15. St. Louis County Department of Public Health (stlouiscountymo.gov)
  16. Effective property tax rate: Bolthole Index county data
  17. Median property tax bill: Bolthole Index county data

Written October 24, 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 Des Peres

Des Peres’s own rules

  • Building code adoptedAdopted (with conditions)

    Buildings and structures within Des Peres city limits.

    • The ordinance adopts the listed 2018 ICC codes together with local amendments.

    code edition: 2018 (International Building, Residential, Swimming Pool and Spa, Existing Building, Fire, and Property Maintenance Codes)

    “AN ORDINANCE AMENDING CHAPTER 6. BUILDING AND BUILDING REGULATIONS TO ADOPT THE 2018 INTERNATIONAL BUILDING CODE, THE 2018 INTERNATIONAL RESIDENTIAL BUILDING CODE, THE 2018 INTERNATIONAL SWIMMING POOL AND SPA CODE, THE 2018 INTERNATIONAL EXISTING BUILDING CODE, THE 2018 INTERNATIONAL FIRE CODE, AND THE 2018 INTERNATIONAL PROPERTY MAINTENANCE CODE TOGETHER WITH CERTAIN AMENDMENTS THERETO AS THE BUILDING CODE FOR THE CITY OF DES PERES AND EFFECTIVE DATE”
  • InspectionsRequired

    Residential work covered by a Des Peres building permit.

    • Inspection must be scheduled at least 24 hours in advance by email to the Building/Public Works Department.

    advance scheduling: >= 24 hours

    “Inspections must be scheduled at least 24 hours in advance. Must email the Building/Public Works Department (Permits@desperesmo.org) to schedule inspection.”
  • Certificate of occupancyLimited

    Commercial occupancy within Des Peres city limits.

    • The application must be accompanied by a business-license application.
    • This source does not establish a residential certificate-of-occupancy requirement.

    commercial occupancy permit fee: 50 USD

    “APPLICATION FOR COMMERCIAL OCCUPANCY PERMIT [...] $50.00 PERMIT FEE [...] APPLICATION MUST BE ACCOMPANIED BY AN APPLICATION FOR BUSINESS LICENSE”
  • Local zoningPresent (with conditions)

    Land within Des Peres city limits.

    • The city directs users to Appendix C, Zoning District Regulations, for the zoning code.
    “The City has a variety of Zoning Districts (links listed for each designation to the left). The Zoning Code can be reviewed in its entirety by using the following link: Appendix C - Zoning District Regulations”
  • Zoning districtsPublished (with conditions)

    Zoning districts within Des Peres city limits.

    • The city directs users to Appendix C for the complete zoning regulations and links a zoning map.
    “The City has a variety of Zoning Districts (links listed for each designation to the left). The Zoning Code can be reviewed in its entirety by using the following link: Appendix C - Zoning District Regulations.”
  • Subdividing landRegulated (with conditions)

    Subdivision of land within Des Peres city limits.

    • The city permit page identifies a Petition for Subdivision; detailed review standards were not retrieved.
    “LAND MANAGEMENT PERMITS [...] Petition for Subdivision”
  • Building in a floodplainRequired

    Development in a Special Flood Hazard Area or floodplain within Des Peres city limits.

    • Floodway development requires certification before permit issuance that the proposed development will cause no increase in base flood elevations.
    • New or substantially improved residential buildings must have the lowest floor one foot above base flood elevation.
    • The cited form states Ordinance No. 2711 was adopted January 12, 2015.

    residential lowest-floor elevation: 1 foot above base flood elevation (new or substantially improved residential building)

    “The undersigned hereby makes application for a permit to develop in the Special Flood Hazard Area (SFHA) or “floodplain.””
  • Permit feesPublished (with conditions)

    Residential building permits within Des Peres city limits.

    • The residential form also requires a refundable escrow deposit; its amount is not stated in the retrieved excerpt.

    plan review fee: 100 USD (due at time of submittal) · permit fee: per 6 USD per $1,000 construction cost (collected when permit is picked up)

    “Processing/plan review fee of $100 due at time of submittal [...] Permit Fee ($6 per $1,000) collected when permit is picked up”
  • Permit processPublished (with conditions)

    Residential building permits within Des Peres city limits.

    • Site plan is not required for interior residential remodels.
    • The stated normal review time is 7–10 business days and no expedited review is offered.

    normal review time: 7-10 business days (no expedited review process)

    “Normal permit review time is 7-10 business days. We do not offer an expedited review process.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Des Peres or St. Louis County directly.

  • Owner-builder exemption — Owner-built residential construction within Des Peres city limits.
  • Minimum dwelling size — Residential zoning districts within Des Peres city limits.
  • Minimum lot size — Residential zoning districts within Des Peres city limits.
  • Setbacks — Residential zoning districts within Des Peres city limits.
  • Lot coverage — Residential zoning districts within Des Peres city limits.
15 more unanswered
  • Building height
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • 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 Des Peres publishes no rule on the point, not that none exists. St. Louis County’s page lists the county offices to call.

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