Bolthole Index

St. Louis County, Missouri

Zoning, building permits and septic rules in Crestwood, Missouri

Crestwood, Missouri sets its own zoning inside city limits through the Development Code1. Building, plumbing and electrical codes are St. Louis County's, adopted by the city, and the county provides the code enforcement2. We could not confirm who issues septic permits inside the city; St. Louis County Department of Public Health is the office to ask3.

At a glance

Zoning
City of Crestwood Development Code, with R-1 through R-5, C-1, M-1 and planned districts4
Building codes
St. Louis County codes adopted by the city; county provides enforcement2
R-1 minimum lot
20,000 square feet, 100 feet wide at the building line5
R-1 setbacks
45 ft front, 12 ft side, 35 ft rear (or 20% of lot depth, up to 50 ft)6
R-1 height and coverage
35 ft and 2 1/2 stories; buildings cover at most 30% of the lot78
Septic
Not confirmed inside city limits; ask St. Louis County Department of Public Health3

Who to call

Zoning

City of Crestwood City Planning & Economic Development

Zoning requests, site plan review, Planning Commission and Board of Zoning Adjustment support in Crestwood

314-729-4781

Building permits

City of Crestwood Department of Public Works

Residential zoning review permits and submittal requirements in Crestwood

314-729-4720

One Detjen Drive, Crestwood, MO 63126

Septic permits

St. Louis County Department of Public Health

Onsite wastewater (septic) permitting authority for St. Louis County, to be confirmed for addresses inside Crestwood

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 Crestwood means bringing your own water and power. The kit we’d start with:

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Does Crestwood, MO have zoning, and what does it mean for lot size and setbacks?

Crestwood divides the city into zoning districts under its own Development Code1. The districts are R-1 through R-5, C-1, M-1 and several planned development districts4.

In the R-1 single-family district, a lot needs at least 20,000 square feet, 100 feet of width at the building line and 150 feet of depth5. R-1 front yards are 45 feet, side yards 12 feet (8 feet on a lot too small to meet the standard) and rear yards 35 feet or 20% of lot depth, whichever the table applies, up to 50 feet6. Buildings may cover 30% of an R-1 lot8. A principal building in R-1 may reach 35 feet and 2 1/2 stories; a detached garage is limited to 15 feet and other accessory structures to 10 feet7.

Other districts have different numbers, so check your parcel's district on the city's zoning map with the City Planner9.

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

Crestwood adopts St. Louis County's building, residential, existing buildings, mechanical, plumbing and electrical codes by reference2. Under the city's code, the county provides code enforcement services for those codes inside Crestwood2.

The city's Department of Public Works publishes submittal requirements for residential zoning review permits, and new construction must also come with a tree and landscaping permit application10. Where a municipality contracts with the county for code enforcement, municipal zoning approval comes before a county permit is issued11. The county's building permit rule itself is written for unincorporated St. Louis County, so Crestwood addresses start with the city. We could not confirm the exact counter that issues the final building permit or the inspection schedule for a new home; call Crestwood Public Works at 314-729-472010.

An occupancy permit is tied to new uses, alterations and conversions, and cannot issue for a use that breaks the zoning article12.

How do septic permits work inside Crestwood?

We could not confirm whether a home inside Crestwood may use, or must avoid, a septic system. The state requires a construction permit before installing or repairing most onsite wastewater systems, with some single-family lots exempt13. For St. Louis County the state lists the county Plumbing Department and the county Department of Public Health as ordinance authorities, and incorporated areas may be handled differently3.

Before planning any septic system, ask St. Louis County Department of Public Health and the City of Crestwood which one applies to your address14. Application fees for onsite systems are temporarily suspended as of August 28, 2026, according to the state13.

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

We could not confirm any Crestwood rule on RV living, tiny homes or manufactured homes; the zoning text we reviewed does not address them. Ask the City Planner before buying or parking anything, because Crestwood's zoning decides where dwellings are allowed19.

Building a home in Crestwood: the steps, in order

  1. Confirm your parcel's zoning district and lot standards with the City Planner9.
  2. Prepare the survey, site plan, floor plans and stormwater plan that the city lists for new dwellings, plus the tree and landscaping application10.
  3. Get city zoning approval; county permits for contracting municipalities follow municipal approval11.
  4. Ask Public Works who issues the building permit and inspections10.
  5. If the lot has no sewer connection, confirm septic rules with St. Louis County Department of Public Health before design14.
  6. A driveway is required for each single-family residence, and the owner builds and maintains it15.

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

For land outside Crestwood city limits, see the St. Louis County page; the county's unincorporated rules do not apply inside Crestwood1. Floodplain development in mapped flood hazard areas requires a permit in Missouri16, and we could not confirm when Crestwood requires its floodplain certification. A well permit is required in Missouri to construct or repair a water well17.

St. Louis County's effective property tax rate is 1.2%18.

Watch-outs

  • We could not confirm who issues septic permits inside Crestwood; ask St. Louis County Department of Public Health before relying on a septic system3.
  • The code edition the city enforces is not fully settled; confirm with Crestwood Public Works before design2.
  • Zoning numbers above are for the R-1 district only; other districts differ5.

Sources

  1. City of Crestwood, MO Zoning Districts And Use Standards (Development Code Chapter 26, Article IV) (Crestwood), quoted and re-checked
  2. Chapter 7 Buildings and Building Regulations - City of Crestwood, MO (eCode360) (Crestwood), quoted and re-checked
  3. OWTS Construction Permit Process — St. Louis County authorities, quoted and re-checked
  4. City of Crestwood, MO Zoning Districts And Use Standards (Development Code Chapter 26, Article IV) (Crestwood), quoted and re-checked
  5. City of Crestwood, MO Zoning Districts And Use Standards (Development Code Chapter 26, Article IV) (Crestwood), quoted and re-checked
  6. City of Crestwood, MO Zoning Districts And Use Standards (Development Code Chapter 26, Article IV) (Crestwood), quoted and re-checked
  7. City of Crestwood, MO Zoning Districts And Use Standards (Development Code Chapter 26, Article IV) (Crestwood), quoted and re-checked
  8. City of Crestwood, MO Zoning Districts And Use Standards (Development Code Chapter 26, Article IV) (Crestwood), quoted and re-checked
  9. City of Crestwood City Planning & Economic Development (cityofcrestwood.org)
  10. City of Crestwood Department of Public Works (cityofcrestwood.org)
  11. Chapter 1115 - Building Code, quoted and re-checked
  12. Chapter 7 Buildings and Building Regulations - City of Crestwood, MO (eCode360) (Crestwood), quoted and re-checked
  13. OWTS Construction Permit Process, quoted and re-checked
  14. St. Louis County Department of Public Health (stlouiscountymo.gov)
  15. Chapter 7 Buildings and Building Regulations - City of Crestwood, MO (eCode360) (Crestwood), quoted and re-checked
  16. Floodplain Forms (Missouri statewide rule), quoted and re-checked
  17. Water Wells - PUB2945, quoted and re-checked
  18. Effective property tax rate: 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 Crestwood

Crestwood’s own rules

  • Building code adoptedAdopted

    Building, residential, existing buildings, mechanical, plumbing, electrical and explosives codes applied inside Crestwood city; the city adopts St. Louis County's codes by reference

    • Adopted codes are St. Louis County codes 'as the same may be amended from time to time'.
    • Listed approval dates: building, residential, existing buildings and plumbing as approved by St. Louis County December 18, 2019 (building, residential, existing buildings: ordinance 27,654), mechanical December 5, 2019, plumbing June 4, 2019, electrical June 11, 2019, explosives code November 6, 1997.
    • Under section 7-1.1 the county provides the city's code enforcement services for building, residential, existing buildings, mechanical, plumbing, electrical and explosives codes.
    • Edition is not fully settled by the text read: a city web page surfaced in search (not opened) referred to a 2015 International Residential Code ordinance. Confirm with the city before relying on an edition.
    “(1) building (as approved by st. louis county on december 18, 2019, ordinance 27,654)”
  • Certificate of occupancyLimited

    New use, change of use, or conversion of a building or land inside Crestwood city

    • Occupancy permit is tied to new uses, extensions or alterations of existing uses, and conversions; whether a completion certificate is issued for a newly built single-family house was not stated in the text read.
    • An occupancy permit cannot issue for a use or change in use that does not conform to the zoning article.
    “no occupancy permit shall be issued for any use or change in use unless such use or change in use is in conformity with the provisions of this article.”
  • Local zoningPresent

    Land inside Crestwood city limits, Missouri, under the city's own Development Code (Chapter 26) zoning districts

    • Applies only inside city limits; unincorporated St. Louis County land is not covered by this ordinance.
    • eCode360 table of contents states the code 'includes legislation through 09-08-2026'; amendments after that date were not checked.
    “for the purpose of regulating and restricting the use and development of land and buildings, the city is hereby divided into the zoning districts listed and described in subsection a of this section and as shown on the official zoning map”
  • Zoning districtsPublished (with conditions)

    Zoning districts inside Crestwood city (R-1 through R-5, C-1, M-1 and planned development districts)

    • Districts R-1 through R-5, C-1, M-1, PD-R, PD-C, PD-M and PD-MXD appear in Article IV; the W-ROW Watson Road overlay is also referenced.
    • Official zoning map is adopted by reference in the same section; not opened.
    “table 26-14 district classification code designation intent statement r-1 single-family residential (not less than 20,000 square feet)”
  • Minimum lot sizeDistrict specific

    R-1 single-family residential district (not less than 20,000 square feet) inside Crestwood city

    • Table 26-16 footnote markers (the '2' after the district name) were not read; footnote text not verified.
    • Lots smaller than required may still be used for listed uses; side yard reductions apply (see setbacks claim).

    minimum lot area, R-1: >= 20000 square feet · minimum width at building line, R-1: >= 100 feet · minimum width at street right-of-way, R-1: >= 50 feet · minimum lot depth, R-1: >= 150 feet

    “r-1 single-family residential 2 20,000 square feet 100 50 150 30% 45 12 35 or 20% of lot depth, but not greater than 50 2 1/2 but not more than 35 15 10”
  • SetbacksDistrict specific

    R-1 single-family residential district (not less than 20,000 square feet) inside Crestwood city

    • Rear setback is 35 feet or 20% of lot depth, but not greater than 50 feet, as the table reads.
    • Lots with less area or width than required may use a reduced side yard under section 26-16 subsection a: 8 feet for R-1.
    • Corner-lot and double-frontage rules and table footnotes in section 26-16 were not fully read.

    front yard setback, R-1: 45 feet · side yard setback, R-1: 12 feet (8 feet for a nonconforming lot under section 26-16 subsection a) · rear yard setback, R-1: 35 feet (or 20% of lot depth, but not greater than 50 feet)

    “r-1 single-family residential 2 20,000 square feet 100 50 150 30% 45 12 35 or 20% of lot depth, but not greater than 50 2 1/2 but not more than 35 15 10”
  • Lot coverageDistrict specific

    R-1 single-family residential district (not less than 20,000 square feet) inside Crestwood city

    • Maximum coverage applies to buildings and structures as stated in Table 26-16.

    maximum coverage of buildings and structures, R-1: <= 30 percent

    “r-1 single-family residential 2 20,000 square feet 100 50 150 30% 45 12 35 or 20% of lot depth, but not greater than 50 2 1/2 but not more than 35 15 10”
  • Building heightDistrict specific

    R-1 single-family residential district (not less than 20,000 square feet) inside Crestwood city

    • Principal building height is 2 1/2 stories but not more than 35 feet, as the table reads.
    • The table header reads 'principal boulevard (stories/feet)'; the meaning of 'boulevard' was not explained in the text read.
    • Detached garage 15 feet and other accessory structures 10 feet per the table.

    principal building height, R-1: <= 35 feet (2 1/2 stories) · detached garage height, R-1: <= 15 feet · other accessory structure height, R-1: <= 10 feet

    “r-1 single-family residential 2 20,000 square feet 100 50 150 30% 45 12 35 or 20% of lot depth, but not greater than 50 2 1/2 but not more than 35 15 10”
  • Driveway accessRequired

    Driveways for single-family residences inside Crestwood city

    • Driveway surfacing must keep mud and dirt off sidewalks and streets.
    • Shared driveways serving two or more single-family residences are not allowed except by special permit for hardship.
    “each single-family residence shall have its own separate driveway, and the owner shall be responsible for its proper construction and maintenance.”

Still unanswered

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

  • Owner-builder exemption — Owner-builder construction of a home inside Crestwood city
  • Inspections — Inspections for a new home inside Crestwood city
  • Minimum dwelling size — Minimum floor area of a single-family house in Crestwood city
  • Living in an RV — Long-term RV occupancy on private land inside Crestwood city
  • Camping on your land — Temporary camping on private land inside Crestwood city
13 more unanswered
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Subdividing land
  • Building in a floodplain
  • 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 Crestwood 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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