St. Louis city, MO Building Permits & Zoning

St. Louis city, Missouri requires a building permit for nearly all construction, alteration, or demolition, issued by the Building Division¹. The whole city is zoned under Title 26 of the City Code, and the Zoning Section reviews every building and occupancy permit for compliance with it². This is Missouri's only independent city, fully built out and served by public sanitary sewer through the Metropolitan St. Louis Sewer District, so there is no unincorporated rural land here and a private septic system is not the norm³.

At a glance

Building permit: Required citywide for nearly all construction, alteration, or demolition¹
Zoning: Yes, citywide under Title 26 of the City Code; every permit is reviewed for zoning compliance²
Septic: Not the norm; the city requires connection to the Metropolitan St. Louis Sewer District's public sewer system³
Owner-builder exemption: Unconfirmed; the city's own permit pages don't state a clear owner-builder exemption⁴
Population density: About 4,563.8 people per square mile, among the densest jurisdictions in this dataset⁵
Distance to metro area: 0 miles; St. Louis city is itself the metro core⁶

Who to call

Building permits

City of St. Louis Building Division

Enforces the city building code, issues building permits, conducts inspections, and enforces zoning ordinances citywide

(314) 622-3313

[email protected]

1200 Market Street, City Hall, Room 426, St. Louis, Missouri 63103-2826

Online permits →

Zoning

City of St. Louis Zoning Section

Administers and enforces the City of St. Louis Zoning Code Ordinance (Title 26); reviews building and occupancy permits for zoning compliance

(314) 622-3666

[email protected]

1200 Market Street, Room 400, St. Louis, Missouri 63103

Online permits →

Zoning

City of St. Louis Zoning Section — Zoning FAQ

The Zoning Section's own published answers on setbacks, building lines, and lot lines

Septic permits

Metropolitan St. Louis Sewer District (MSD) Customer Service

Public sanitary sewer service and connections for St. Louis city; the practical alternative to septic here

(314) 768-6260

2350 Market Street, St. Louis, MO 63103-2555

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

Do you need a building permit in St. Louis city, Missouri?

Yes. The Building Division enforces the city building code, issues building permits, conducts building inspections, and enforces zoning ordinances citywide¹⁷. Missouri's building-code statute for county commissions, RSMo 64.170, only reaches counties of the first and second classification, so St. Louis city, as Missouri's only independent city, sets and enforces its own building code rather than operating under that county statute⁸. Because the Zoning Section reviews every building and occupancy permit application for compliance with Title 26 of the City Code before it's approved, your building permit application effectively doubles as a zoning check⁹². This guide could not confirm a specific owner-builder exemption on the city's own permit pages, so budget for a licensed contractor or confirm directly with the Building Division whether you can pull your own residential permit⁴⁷.

Who is the St. Louis city building department, and how do you reach them?

The Building Division's main line is (314) 622-3313, or email [email protected]⁷. Phone hours run Monday through Friday, 8:00 a.m. to 4:45 p.m., with Permits Section office hours Monday through Thursday 8:00 a.m. to 4:30 p.m. and Friday 8:00 a.m. to 4:00 p.m.⁷. The office is at 1200 Market Street, City Hall, Room 426, St. Louis, Missouri 63103-2826⁷. Zoning questions go directly to the Zoning Section at (314) 622-3666 or [email protected], in Room 400 of the same City Hall address⁹.

Does St. Louis city have zoning?

Yes, every parcel in the city sits in a zoning district under Title 26 of the 1994 City of St. Louis Revised Code, and the Zoning Section reviews all commercial occupancy and building permits for compliance with it²⁹. A permit is approved as a use allowed by right, referred to a Conditional Use hearing, or denied, and a denial can be appealed to the Board of Adjustment⁹. Setbacks depend on the zoning district: rear setbacks apply to primary structures and vary by district, though residential garages and carports along an alley can sit as close as 5 feet from the rear boundary, and where there isn't enough nearby to establish a front building line, the Zoning Section can order a survey for $25¹⁰. Because St. Louis city has no unincorporated land and no large-lot rural zoning district in this dataset, treat this as an infill or redevelopment purchase, not an acreage purchase²⁵.

How does sewer and septic work in St. Louis city?

St. Louis city is served by public sanitary sewer through the Metropolitan St. Louis Sewer District (MSD), so a private septic system is not the default and is effectively not applicable for most city parcels³. To establish new sewer service, including when you're moving into a property, MSD requires a phone call to (866) 281-5737 to set up an account; this can't be done online or by email¹¹. For an active sewer emergency, such as a backup or serious street flooding, MSD's Customer Service line at (314) 768-6260 is staffed around the clock¹¹. Statewide, Missouri requires a construction permit before installing or repairing most onsite wastewater treatment systems, generally including residential lots under 3 acres, but that rule targets areas without sewer access, which describes almost no land inside St. Louis city¹². If you find a St. Louis city parcel without a sewer connection, contact the Building Division before assuming a private septic system is an option⁷.

Can you live in an RV or tiny home on your land in St. Louis city?

Nothing this guide could confirm on the city's own pages this session directly answers whether you can live in an RV on your property in St. Louis city, so don't assume it's allowed just because there's no rule you happened to find². Because every parcel here is zoned and the Zoning Section reviews building and occupancy permits against Title 26 of the City Code, any structure you plan to live in, including a tiny home, still needs to go through the same permit and zoning review as a conventional home⁹¹. Call the Zoning Section directly before you plan on an RV or tiny home as a residence here, since this is dense, fully built-out city land, not the kind of rural parcel where that question usually comes up⁹⁵.

Building or buying in St. Louis city: the steps, in order

Look up your parcel's zoning district before you make an offer, since the Zoning Section reviews every project against it⁹².
Confirm your parcel's sewer connection with the Metropolitan St. Louis Sewer District; call (866) 281-5737 if you need to establish new service¹¹.
Apply for your building permit with the Building Division at 1200 Market Street, City Hall, Room 426, or by emailing [email protected]⁷.
Expect your permit application to be reviewed for zoning compliance as part of the same process; a denial can be appealed to the Board of Adjustment⁹.
If your setback depends on matching an existing building line and there isn't enough nearby to go on, order a $25 building line survey from the Zoning Section¹⁰.
Schedule inspections with the Building Division as work proceeds, using the phone or email above⁷.

What to check before you buy land in St. Louis city

St. Louis city is the densest jurisdiction in this guide, at roughly 4,563.8 people per square mile, and it sits right in the metro core at 0 miles from the nearest metro area, so this is an urban property purchase, not a rural-land purchase⁵⁶. A typical home here is valued around $186,876, and where farmland exists at the city's edges it runs about $10,928 an acre¹³¹⁴. The city gets about 41.8 inches of precipitation a year and has seen severe drought in only about 3.2% of recent years¹⁵¹⁶. Budget for an effective property tax rate near 1%, with a median bill around $1,935 a year, and a typical home insurance premium near $2,303 a year¹⁷¹⁸¹⁹. Confirm your parcel's sewer connection and zoning district before you close, since both are non-negotiable here and neither works the way a rural county's rules would¹¹⁹.

Watch-outs

St. Louis city has no unincorporated rural land: it's Missouri's only independent city, fully zoned and fully served by public sewer, so this guide is written for a city purchase, not a rural homestead²³.
This guide could not confirm a St. Louis city rule on RV or tiny-home occupancy specifically; call the Zoning Section before you plan on either as a residence⁹.
This guide could not confirm a specific owner-builder permit exemption on the city's own pages; confirm directly with the Building Division before assuming you can pull your own permit⁷⁴.

Sources

Written September 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.

How St. Louis City scores

Seclusion16100% ev.

Self-Sufficiency1573% ev.

Admin Boringness4690% ev.

Durability52100% ev.

Property Autonomy47100% ev.

Carry Cost63100% ev.

Evidence strength: 92%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$187kTypical home

1%Property tax

$10,928Land / acre

41.8"Annual rain

3.2% of yrsSevere drought

13.2 / yr (+11.3)Mid-century 100°F days

16.6 daysMid-century dry spell

1.89" (+9%)Mid-century 1-day rain

1.84×Wildfire change factor

100%Forward climate coverage

$2,303Home insurance / yr

0.7% / yrInsurance growth

1.44%Nonrenewal rate

county median (2+ published ZIPs)Insurance basis

1,754,852People within 30 min

4,070,856People within 2 hr

1,291,158Radius comparison (15 mi)

4,563.8People / sq mi

0.3%Federal land

56.5°FAvg temp

Answers from the rulebook for St. Louis City

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

St. Louis City rules

Building permitRequired
This large urban jurisdiction's Building Division enforces the City Building Code (Title 25) and requires a building permit to legally start construction.
City of St. Louis Building Division ↗Scouted from the county site, not yet independently re-checked
County-wide zoningPresent
The Building Division's Zoning Section administers the Zoning Code in Title 26 with single-family, two-family, and commercial districts.
City of St. Louis Zoning Section ↗Scouted from the county site, not yet independently re-checked

Missouri rules that apply here

Building code adoptedPartial
Missouri statewide legal framework for building-code adoption by counties and other communities; the statutes authorize local adoption rather than establishing one uniformly adopted statewide building code.
- County authority under RSMo 64.170 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 under RSMo 64.170 to 64.200.
- The adoption vote is limited to voters in the affected area; a code affecting a county is not voted on by citizens of incorporated territory.
- A county adopting under RSMo 64.180 must use a current nationally recognized building code edition from calendar year 1999 or later, as amended.
- A county building ordinance may not conflict with liquefied petroleum gas installation requirements governed by RSMo 323.020.
- A community may incorporate a code by reference only if it otherwise has legal power to adopt the ordinance.
- A code incorporated by reference must be filed with the community clerk and available for public inspection for 90 days before adoption.
- An ordinance adopting a code by reference must state the penalty separately rather than incorporate the penalty by reference.
- RSMo 67.280 defines community to include any county, fire protection district, or municipality, and municipality to include an incorporated city, town, or village.
“Because fire and building codes are adopted at the local level in Missouri”
RSMo Section 64.170 ↗Re-checked Sep 11, 2026
2 more reviewed findings on this topic
- Partial — Residential building-code adoption by Missouri counties, particularly construction in unincorporated county territory.
  “the county commission in all counties of the first and second classification [...] is for this purpose empowered [...] to adopt [...] regulations”
  RSMo § 64.170 — County commissions control construction; issue building permits ↗Re-checked Oct 1, 2026
- Partial — County adoption of residential building codes in Missouri, with the resulting regulations applicable to unincorporated territory when adopted under the statutory authority.
  “the county commission in all counties of the first and second classification, as provided by law, is for this purpose empowered”
  RSMo Section 64.170 — County commissions control construction; issue building permits ↗Re-checked Oct 1, 2026
Who permits septicMixed (with conditions)
Onsite wastewater treatment systems statewide in Missouri.
- DHSS administers minimum standards and permits through DHSS, local contract authorities, or local authorities operating under ordinance.
- County or city governments may adopt standards stricter than the state standard.
- DNR regulates lagoons serving anything other than single-family residences, systems discharging to surface waters, systems treating flows greater than 3,000 gallons per day and dispersing through soil absorption systems, and industrial wastewater systems.
- DNR approval is required for subdivisions, mobile home parks, and campgrounds when OWTS use is planned.
domestic wastewater flow threshold: <= 3000 gallons per day (DNR regulates systems with flows greater than 3,000 gallons per day when wastewater is dispersed through soil treatment or absorption systems)
“DHSS OWTS permitting falls under one of three authority types: DHSS Onsite Program, Local Authority (contract), or Local Authority via Ordinance. The application process varies by permitting authority.”
OWTS Construction Permit Process ↗Re-checked Oct 1, 2026
One more reviewed finding on this topic
- Mixed — Missouri wastewater treatment systems, including domestic onsite systems, larger-flow systems, direct discharges, lagoons, subdivisions, and industrial wastewater.
  “In Missouri, different state and local agencies are responsible for regulating wastewater treatment systems.”
  On-site Septic Systems and Subdivisions ↗Re-checked Sep 11, 2026
Septic permitRequired
Installing or repairing most onsite wastewater treatment systems in Missouri, including residential systems subject to state permitting.
- A construction permit is required before installing or repairing most OWTS.
- Some single-family residential lots may be exempt.
- For residential property less than three acres, a permit is required; the exemption does not apply in some counties, so the county authority must be checked.
- Work should not begin until a permit is issued or an exemption is confirmed.
- Effective August 28, 2026, application fees for onsite sewage disposal system construction, modifications, and repairs are temporarily suspended.
residential lot threshold: < 3 acres (The exemption does not apply in some counties.) · temporary permit-fee suspension effective date: 2026-08-28 (Applies to application fees associated with onsite sewage disposal system construction, modifications, and repairs.)
“A construction permit is required before installing or repairing most onsite wastewater treatment systems (OWTS). Some single family residential lots may be exempt from permitting.”
OWTS Construction Permit Process ↗Re-checked Sep 11, 2026
3 more reviewed findings on this topic
- Required — Installing or repairing most onsite wastewater treatment systems.
  “A construction permit is required before installing or repairing most onsite wastewater treatment systems (OWTS). Some single family residential lots may be exempt from permitting.”
  OWTS Construction Permit Process ↗Re-checked Sep 26, 2026
- Required — Installing or repairing most onsite wastewater treatment systems statewide in Missouri.
  “A construction permit is required before installing or repairing most onsite wastewater treatment systems (OWTS). Some single family residential lots may be exempt from permitting.”
  OWTS Construction Permit Process ↗Re-checked Oct 1, 2026
- Required — Proposed campgrounds, mobile home parks, and subdivisions planning to use onsite wastewater treatment systems anywhere in Missouri.
  “DNR must approve subdivisions, mobile home parks and campgrounds if the use of OWTS is planned.”
  OWTS Construction Permit Process ↗Re-checked Oct 1, 2026
Septic inspectionLimited
Inspection or evaluation of existing onsite wastewater systems in connection with Missouri real-estate transfers.
- Local public health agencies generally no longer inspect existing systems for real-estate transfers.
- A private licensed inspector may perform an inspection or evaluation.
- A lender, buyer, or other transaction participant may require an assessment.
- Some local standards may be more stringent than state regulations.
- Inspections and evaluations are distinct; an inspection includes a hydraulic test, while an evaluation does not.
“For the most part, local public health agencies no longer inspect existing systems related to real estate transfer. The help of a licensed inspector can be obtained to check the condition of the system.”
Onsite Wastewater Treatment System Inspections Versus Evaluations ↗Re-checked Sep 11, 2026
One more reviewed finding on this topic
- Limited — Inspections of existing onsite sewage systems in connection with property sales statewide in Missouri.
  “Missouri Department of Health and Senior Services' (DHSS) rules governing onsite sewage systems cover minimum construction requirements, system inspections at the time of property sales, and requirements for percolation testers and soil evaluators.”
  Resources ↗Re-checked Oct 1, 2026
Off-grid sanitationLimited
Off-grid domestic wastewater treatment using onsite wastewater treatment systems where central sewer service is unavailable.
- Onsite systems treat and dispose of domestic sewage on the property where generated.
- A construction permit is generally required, including for residential property less than three acres, subject to county-specific exceptions.
- Wastewater may not be discharged into a road ditch or onto the ground.
- Local permitting authorities may impose additional requirements.
residential lot threshold: < 3 acres (The exemption does not apply in some counties.)
“Onsite wastewater treatment systems are sometimes referred to as "septic systems." These systems treat and dispose of domestic sewage on the property where it is generated.”
Frequently Asked Questions ↗Re-checked Sep 11, 2026
One more reviewed finding on this topic
- Allowed (with conditions) — Use of onsite wastewater treatment systems as off-grid sanitation where central sewer service is unavailable in Missouri.
  “In Missouri, where central sewer service is not available, homeowners and small business owners use various types of onsite wastewater treatment systems (OWTS).”
  Onsite Wastewater Treatment ↗Re-checked Oct 1, 2026
Well permitRequired
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.
- Individuals must test and become licensed or permitted to do business in Missouri for regulated well construction work.
- A non-restricted permit is required for drilling, constructing, repairing, reconstructing, plugging, or installing pumps or pumping equipment in a well.
- Permit fees are $150 for each applicable water-well, pump, heat-pump, monitoring-well, or mineral-test-hole permit, effective April 1, 2024 according to the page.
- Permits expire and must be renewed annually; renewal is due by October 1, and permits are cancelled if not renewed by October 31.
permit fee: 150 USD (for each applicable permit; effective April 1, 2024) · permit renewal deadline: October 1 (permits are cancelled if not renewed by October 31)
“A non-restricted permit is required to drill, construct, repair, reconstruct, plug, or install pumps or pumping equipment in a well.”
Well and Pump Installation Contractor Permitting ↗Re-checked Oct 1, 2026
Agricultural exemptionAvailable (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.
- RSMo section 64.890 does not apply to incorporated portions of counties.
- It does not apply to raising crops, livestock, orchards, or forestry, or to seasonal or temporary impoundments used for rice farming or flood irrigation.
- For purposes of the statute, rice-farming or flood-irrigation berms are small berms no more than eighteen inches high placed around a field to hold water.
- The farm-building and farm-structure exemption applies only in an area not within the area shown on the flood hazard area map.
- The statute preserves existing-lawful-use rights, judicial review of reasonableness, and authorized public utility services; it also preserves ordinances or orders adopted before March 4, 1991 under section 64.890(3).
rice-farming or flood-irrigation berm height: <= 18 inches (The statutory definition applies to 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 [...]”
RSMo Section 64.890 ↗Re-checked Oct 1, 2026
2 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.”
  RSMo Section 64.003 — Farm buildings and farm structures ↗Re-checked Sep 11, 2026
- 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 [...]”
  RSMo Section 64.003 ↗Re-checked Oct 1, 2026
Subdividing landLimited
Subdivision plats in the unincorporated areas of counties covered by RSMo section 64.070 after the county commission adopts subdivision regulations.
- The county commission must first adopt subdivision regulations.
- The plat must first be submitted to the planning commission.
- If the county planning commission does not report upon the plat within thirty days, it may then be deemed approved.
- If amended or rejected by the planning commission, the action may be overruled and the plat approved only by the county commission, with the reasons for overruling spread upon the county commission minutes.
- The recorder of deeds may not record the plat until receiving a certificate of authority from the county zoning enforcement officer.
- The statute also permits a county planning commission, upon written request of an incorporated area's legislative body where there is no municipal planning commission, to pass upon subdivision plats within that incorporated area; those plats are subject to county planning commission rules and approval procedures.
planning commission reporting period: 30 days (If no report is made, the plat may then be deemed approved.)
“After the county commission shall have adopted such subdivision regulations, no plat of a subdivision of land within the unincorporated area of such county [...]”
RSMo Section 64.070 ↗Re-checked Oct 1, 2026
2 more reviewed findings on this topic
- Regulated (with conditions) — Subdivisions in which onsite wastewater treatment systems are planned.
  “DNR must approve subdivisions, mobile home parks and campgrounds if the use of OWTS is planned.”
  OWTS Construction Permit Process ↗Re-checked Sep 26, 2026
- Limited — Subdivision regulations adopted by Missouri cities, towns, or villages under RSMo section 89.410.
  “The planning commission shall recommend and the council may by ordinance adopt regulations governing the subdivision of land within its jurisdiction.”
  RSMo Section 89.410 ↗Re-checked Oct 1, 2026
Driveway accessRequired
Construction or modification of driveways within MoDOT right-of-way statewide.
- A permit is required for construction of driveways and modifications to existing driveways on MoDOT right-of-way.
- An initial online request must be submitted for each planned listed activity.
- Engineered plans, traffic studies, hydraulic analysis, traffic-control plans, surety deposits, or performance bonds may be required depending on the work.
- The rule does not establish a permit requirement for driveways outside MoDOT right-of-way.
“We require you to obtain a permit to work on MoDOT's Right of Way for: Construction of driveways”
Permits | Missouri Department of Transportation ↗Re-checked Sep 11, 2026
Building in a floodplainLimited
Projects including mining, dredging, building construction, and other dirt-moving activities in designated flood hazard areas within participating Missouri jurisdictions.
- The source describes local county or city flood damage reduction ordinances rather than one uniform statewide ordinance.
- The project must be within a participating jurisdiction.
- The project must be within a designated flood hazard area.
- The cited rule does not apply if either condition is absent.
- Covered projects must not raise flood heights.
“Some jurisdictions (for example, county, city) require any projects in certain floodplains do not raise flood heights.”
Laws and Regulations That Might Affect You if You Mine Sand or Gravel From Missouri Streams ↗Re-checked Sep 11, 2026
Permit feesPublished (with conditions)
Missouri Department of Natural Resources air construction permits statewide.
- Fees apply to air construction permits, not to every Missouri building or land-use permit.
- Construction permit fees include a filing fee and an hourly processing fee.
- The filing fee depends on the type of construction permit.
- The listed fees are effective January 1, 2026.
- Fees applicable until December 31, 2025 are available on the Air Construction Permit Fees white sheet.
- A convenience fee is charged for electronic payment.
portable source relocation filing fee: 300 USD · minor permit filing fee: 300 USD · minor permit processing fee: per 100 USD (hour) · general permit filing fee: 700 USD · new source review filing fee: 6000 USD (plus $100 per hour processing fee) · prevention of significant deterioration filing fee: 6000 USD (plus $100 per hour processing fee) · hazardous air pollutant filing fee: 6000 USD (plus $100 per hour processing fee) · temporary or pilot filing fee: 250 USD (plus $100 per hour processing fee)
“Construction permit fees include a filing fee and an hourly processing fee. The filing fee is dependent on the type of construction permit.”
Air Construction Permits ↗Re-checked Sep 11, 2026
Permit processPublished (with conditions)
Permit applications for work on Missouri Department of Transportation right-of-way statewide.
- The process applies to MoDOT right-of-way work.
- Applicants may apply online, contact the area Traffic Specialist, or submit a hard-copy application by mail.
- Additional documentation may be required depending on the work, including site plans, performance bond, certificate of liability, traffic studies, or a meeting with MoDOT personnel.
- After issuance, Missouri One Call, a Notice of Intent, permit and approved-plan retention, and Traffic Specialist contact requirements apply.
- Lane closures require a request at least two working days in advance and authorization before closing lanes.
- The Traffic Specialist must be contacted at least 48 hours before beginning work and for necessary inspections.
lane-closure advance request: >= 2 working days (authorization from MoDOT is also required) · Traffic Specialist pre-work contact: >= 48 hours (before beginning work)
“Contact the Traffic Specialist a minimum of 48 hours prior to beginning work and for all necessary inspections.”
Permit Process | Missouri Department of Transportation ↗Re-checked Sep 11, 2026
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.”
RSMo § 64.850 — County commission may prescribe zoning regulations ↗Re-checked Oct 1, 2026
2 more reviewed findings on this topic
- General — Missouri counties adopting zoning regulations for unincorporated territory.
  “If a majority of the votes cast is in favor of county zoning, the county commission shall proceed with a program of county zoning”
  RSMo § 64.090 — Planning and zoning powers of county commission ↗Re-checked Sep 21, 2026
- Limited — Missouri county zoning of unincorporated land.
  “counties of the second, third or fourth class may, after approval by vote of the people [...] in the unincorporated portions of the county”
  RSMo § 64.090 — Planning and zoning powers of county commission ↗Re-checked Oct 1, 2026
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”
RSMo Section 64.170 — County commissions control construction; issue building permits ↗Re-checked Oct 1, 2026
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”
  RSMo § 64.170 — County commissions control construction and issue building permits ↗Re-checked Sep 21, 2026
- 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”
  RSMo § 64.170 — County commissions control construction; issue building permits ↗Re-checked Oct 1, 2026

Inside cities and towns in St. Louis City

Municipal rules found while researching the county. They apply inside that city or town, not to unincorporated land.

Owner-builder exemptionConditional
A homeowner performing electrical work in the City of St. Louis.
- The homeowner must pass a short Building Division Electrical Section test demonstrating sufficient knowledge of the Electrical Code.
- The property must be an owner-occupied, single-family dwelling.
- The work must be a room addition, repair, or modification to an existing electrical system.
- The homeowner may not apply for permits for service changes, rehabilitation, or new construction; those must be performed by a licensed contractor.
- The City page identifies the applicable electrical code as the 2017 National Electrical Code, adopted by Ordinance 70802 on August 1, 2018.
- The page directs applicants to contact the Building Division Electrical Section at 314-622-3313 or visit Room 425 in City Hall for testing and application information.
homeowner knowledge test: short test (Must determine sufficient knowledge of the Electrical Code to do the work.) · property type: owner-occupied, single-family dwelling · permitted work: room addition, repair, or modification to an existing system · prohibited work: service changes, rehab, or new construction (Must be performed by a licensed contractor.)
“As a homeowner, you can receive an electrical permit under the following conditions: You pass a short test given by the Building Division Electrical Section to determine that you have sufficient knowledge of the Electrical Code to do the work. You are performing work on an owner-occupied, single-family dwelling. You are performing a room addition, repair, or modification to an existing system. You may not apply for permits for service changes, rehab, or new construction. Those need to be performed by a licensed contractor.”
Apply for an Electrical Permit ↗Re-checked Oct 1, 2026
Building code adoptedAdopted
City building, residential, energy, property-maintenance, fire, plumbing, mechanical, fuel-gas, electrical, and zoning codes.
- The listed codes were adopted by City ordinances.
- The source lists multiple code editions and adoption dates.
2018 International Building Code adoption date: 2018-08-01 · 2021 Uniform Plumbing Code adoption date: 2023-02-20
“2018 International Building Code Ordinance 70794 Date adopted: 08-01-18”
Building Codes Adopted by the City ↗Re-checked Sep 26, 2026
InspectionsRequired
Residential occupancy and Housing Conservation District inspections in St. Louis City.
- 100% of City property is in a Housing Conservation District.
- Units must be inspected before occupancy.
- A reinspection is required every three years or upon a change in occupancy for rental dwelling units.
- Owner-occupied properties are exempt from that reinspection requirement.
- Water and electric must be operable at inspection.
“100% of property in St. Louis is located in a Housing Conservation District. Ordinance No. 71835 requires a City Housing Conservation District Inspection of any property located in the district.”
Building Division ↗Re-checked Sep 26, 2026
Local zoningPresent (with conditions)
Land-use zoning throughout the City of St. Louis.
- The City Building Division enforces zoning ordinances.
- Zoning districts and overlays determine applicable use and dimensional requirements.
“The Building Division enforces the City building code, issues building permits, conducts building inspections, demolishes vacant buildings, and enforces zoning ordinances.”
Building Division ↗Re-checked Sep 26, 2026
SetbacksSpecified
Front, side, and rear setbacks for parcels subject to City zoning.
- Setbacks depend on the zoning district.
- Side-yard setbacks may be modified based on lot width in zones A and B and the type or height of the proposed structure.
- Rear-yard setbacks vary by zoning district.
- Residential garages and carports must be 5 feet or less from the alley or rear boundary.
- If there are insufficient nearby structures to establish the building line, a setback may be selected within the range established for the district.
- A $25 building-line survey may be ordered from Zoning.
- A noncompliant setback may lead to permit denial unless resolved, including by a maintenance agreement or Board of Adjustment variance.
building line survey: 25 USD · garage/carport alley or rear-boundary distance: <= 5 feet or less (residential garages/carports)
“Setbacks- front, side, and rear- depend on the zoning district. Once you verify the zoning designation of the parcel, you can look up the applicable setbacks in the zoning code.”
Answers to Common Zoning Questions ↗Re-checked Sep 26, 2026
Driveway accessRequired
Driveway improvements proposed within the public right-of-way or on City property.
- Public-improvement permits are required for improvements in the public right-of-way or on City property.
- The City reviews ADA compliance, accessibility guidelines, right-of-way encroachment conditions, stormwater drainage, utility conflicts, public safety, public health, and other necessary criteria.
- Historic-district, City-landmark, City-park, general-revenue-funded, encroachment, and demolition projects may require additional Cultural Resources Office approval.
“Public improvement permits are required for any improvements proposed within the public right-of-way (ROW) or on City property. Examples include: [...] Sidewalk improvements and driveways”
Apply for a Public Improvement Permit ↗Re-checked Sep 26, 2026
Permit feesPublished (with conditions)
City building-permit applications.
- All City building-permit fees are non-refundable.
- Only the application fee is payable when the application is filed.
- The permit fee is due after final approvals when the permit is ready to issue.
- For estimated construction costs over $3,000, the permit fee is $10 per thousand dollars of estimated construction cost or fraction thereof.
application fee: 25 USD per application · permit fee for estimated cost $0-$1,000: 19 USD (plus $25 application fee) · permit fee for estimated cost $1,001-$2,000: 23 USD (plus $25 application fee) · permit fee for estimated cost $2,001-$3,000: 30 USD (plus $25 application fee) · permit fee over $3,000: per 10 USD per thousand estimated construction cost or fraction thereof (plus $25 application fee)
“All fees paid to the City of St. Louis for building permits are non-refundable. Only the application fee is payable at the time the building permit application is filed.”
Apply for a Building Permit ↗Re-checked Sep 26, 2026
Permit processPublished (with conditions)
City building-permit applications for residential and commercial projects.
- Applications may be submitted online or in person at City Hall.
- The applicant needs the project address, application fee, owner authorization if not the owner of record, and project plans.
- The project may require associated plumbing, electrical, or mechanical permits.
- Review depends on project specifics and assigned City agencies.
- The permit may be printed and must be displayed onsite after approval.
“You can apply in person by bringing your drawings to the Permit office in City hall during business hours , or you can apply online via the button below.”
Apply for a Building Permit ↗Re-checked Sep 26, 2026

Still unanswered

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

Minimum dwelling size — Minimum dwelling size under City zoning and building regulations.
Minimum lot size — Minimum lot size under City zoning regulations.
Lot coverage — Lot coverage under City zoning regulations.
Building height — Building-height limits under City zoning regulations.
Living in an RV — Living in or using an RV or camper as a dwelling on private property in St. Louis city.

5 more unanswered

Camping on your land
Tiny homes
Manufactured homes
Accessory dwellings
Mandatory utility hookup

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 St. Louis City, Missouri

Is St. Louis City a good place to live off-grid or homestead?

St. Louis City scores 26/100 on the Bolthole Index, a weak county profile. Its strengths: manageable long-term carry cost. Watch-outs: workable self-sufficiency basics (41.8″/yr rainfall) and little seclusion — roughly 1,754,852 people within a 30-minute drive.

Do you need a building permit in St. Louis City, Missouri?

St. Louis City generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Missouri Department of Health and Senior Services. 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.

How much does land cost in St. Louis City, Missouri?

Land in St. Louis City runs about $10,928 per acre, based on the latest county data.

What is the water situation in St. Louis City?

St. Louis City gets about 41.8" of rain a year, with severe drought in roughly 3.2% of years.

How remote is St. Louis City?

A representative private-land location has about 1,754,852 people within a 30-minute drive and 4,070,856 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.

Building permits, zoning and land rules in St. Louis city, Missouri