Bolthole Index

McDonald County, Missouri

Building permits, zoning and septic in Town of Southwest City, Missouri

Town of Southwest City, Missouri requires a building permit to erect, move, add to or structurally alter a building or other structure.1 Southwest City has municipal zoning and has adopted the 2018 International Building Code.23 In McDonald County, septic installation and repair permits come from the county health department; Southwest City also imposes private-sewage inspection and public-sewer connection requirements.456

At a glance

Building permits
Required for erection, moving, additions and structural alterations1
Zoning
Municipal districts; ask the City Clerk to inspect the zoning map27
Building code
2018 International Building Code3
Wastewater
Public-sewer connection may be mandatory; county septic permits and town private-system inspection also apply654
Minimum home size
R-1 single-family dwellings: at least 1,000 square feet of living area8
Lot coverage
R-1: all buildings combined may cover no more than 30% of the lot9

Who to call

Building permits

Southwest City Hall / City Clerk

Start here for building and zoning inquiries, the zoning map, and referral to the administrative official.

(417) 762-3767

[email protected]

302 Main St, Southwest City, MO 64863

Building permits

Southwest City building-permit administrative official

Issues building permits under the municipal zoning chapter.

Septic permits

McDonald County Health Department - Environmental

Septic-system permits and repair permits

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 Town of Southwest City means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Town of Southwest City, MO?

Southwest City requires a building permit before a building or other structure is erected, moved, added to or structurally altered; the municipal administrative official issues that approval.1 Southwest City has adopted the 2018 International Building Code.3 Building plans and the proposed use must comply with the zoning ordinance before the town can issue a building permit.1 Ask City Hall about the inspection schedule and any certificate of occupancy before setting a construction or move-in date; we could not confirm those town requirements.

Who issues building permits in Town of Southwest City?

Contact Southwest City Hall and the City Clerk to reach the building-permit administrative official and request the current application instructions.10 The Southwest City building-permit fee schedule is on file in the city offices.1 The permit application calls for duplicate plans drawn to scale.1 Bring the proposed use and site layout to the discussion: Southwest City requires the plans and use to satisfy zoning before a building permit is issued.1 Ask the City Clerk to show you the parcel on the municipal zoning map, which the clerk maintains for public inspection.7

Does Town of Southwest City have zoning and setbacks?

Southwest City has zoning within its incorporated limits, and the City Clerk maintains the zoning map for public inspection.27 In Southwest City’s R-1 Single-Family District, dwellings need at least 1,000 square feet of living area, and a single-family dwelling cannot be a trailer house or mobile home.8 All buildings together, including accessory buildings, may cover no more than 30% of an R-1 lot.9 Detached accessory buildings not used as dwellings may occupy the rear yard with at least 5 feet of clearance from side and rear lot lines, outside public easements.9 Ask the City Clerk for the district’s principal-building setbacks before drawing the house footprint.

How do septic permits work in Town of Southwest City?

Southwest City requires qualifying occupied properties abutting a street, alley or right-of-way containing public sewer to connect when that sewer is within 100 feet of the property line, within 90 days after official notice.6 Where public sewer is unavailable under that rule, Southwest City allows a private sewage disposal system subject to its permit and inspection requirements.6 McDonald County Health Department requires septic installation and repair permits.4 Southwest City’s private-system permit becomes effective only after installation satisfies the Inspector; notify the Inspector before underground portions are covered.5 Coordinate the town inspection and county health approval before excavation.

Can you live in an RV or tiny home in Town of Southwest City?

We could not confirm a complete Southwest City rule for long-term RV occupancy, temporary camping or tiny-home occupancy; ask City Hall about the exact parcel, dwelling design and proposed duration. Southwest City’s R-1 district requires at least 1,000 square feet of living area for a single-family dwelling and excludes trailer houses and mobile homes from that dwelling category.8 Those R-1 restrictions matter when evaluating a small dwelling, but do not establish an RV rule for every district.8 We also could not confirm whether Southwest City allows an independent accessory dwelling unit or offers a general owner-builder exemption; ask the municipal administrative official before purchasing a unit.

Building a home in Town of Southwest City: what are the steps?

  1. Ask the City Clerk to identify the parcel’s Southwest City zoning district on the map available for public inspection.7
  2. Ask Southwest City about public-sewer availability and the connection requirement; if a private system is appropriate, obtain county health septic approval and coordinate the town’s inspection.645
  3. Submit scaled plans to the municipal building-permit administrative official and resolve zoning compliance before construction approval.1
  4. Ask City Hall to identify the applicable floodplain administrator: Missouri requires a permit for all floodplain development.11
  5. Confirm inspections and move-in requirements with City Hall; we could not confirm the town’s general inspection schedule or certificate-of-occupancy rule.

For a parcel outside town limits, read the McDonald County guide: the county’s limited building-permit requirements apply to unincorporated land.12

Watch-outs

  • Southwest City’s R-1 minimum dwelling size is 1,000 square feet of living area; confirm the parcel’s district before buying a tiny home.8
  • A Southwest City sewer-connection requirement can control the wastewater choice even when you planned to install septic.6
  • We could not confirm RV living, private-well approval or general owner-builder exemptions inside Southwest City; ask City Hall to identify the applicable requirements and office.10

Sources

  1. Southwest City building-permit administrative official (ecode360.com)
  2. Article II: Districts And District Regulations - Southwest City, MO (Town of Southwest City), quoted and re-checked
  3. Chapter 500: Building Codes and Regulations - Southwest City, MO (Town of Southwest City), quoted and re-checked
  4. McDonald County Health Department - Environmental (mcdonaldcountyhealth.com)
  5. Chapter 705: Sewers - Southwest City, MO (Town of Southwest City), quoted and re-checked
  6. Chapter 705: Sewers - Southwest City, MO (Town of Southwest City), quoted and re-checked
  7. Article II: Districts And District Regulations - Southwest City, MO (Town of Southwest City), quoted and re-checked
  8. Article II: Districts And District Regulations - Southwest City, MO (Town of Southwest City), quoted and re-checked
  9. Article II: Districts And District Regulations - Southwest City, MO (Town of Southwest City), quoted and re-checked
  10. Southwest City Hall / City Clerk (southwestcity.org)
  11. Floodplain Forms (Missouri statewide rule), quoted and re-checked
  12. McDonald County Commission planning and zoning letter, quoted and re-checked

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 Town of Southwest City

Town of Southwest City’s own rules

  • Building code adoptedAdopted

    Building construction inside Southwest City town.

    • The adopted code is the 2018 International Building Code, published by the International Code Council.
    • The ordinance record identifies Ordinance No. 621 dated 07-14-2020.

    building code edition: 2018 International Building Code

    “The Board of Aldermen adopts the latest building code requirements as stated in the "2018 International Building Code," 2018 Edition, published by the International Code Council.”
  • Local zoningPresent

    Zoning within the incorporated limits of Southwest City town.

    • The code establishes A-1, R-1, R-2, R-3, MP, C-1, C-2, C-3, I-1 and I-2 districts.
    “Be it ordained by the Governing Body of the City of Southwest City, Missouri, that the following zones and regulations be imposed within the incorporated limits of said City.”
  • Zoning districtsPublished

    Zoning districts inside Southwest City town.

    • The zoning map is maintained by the City Clerk and is available for public inspection.
    “The Zoning Map shall be kept and maintained by the City Clerk and shall be available for inspection and examination by members of the public at all reasonable times as any other public record.”
  • Septic inspectionRequired

    Private sewage disposal installations inside Southwest City town.

    • The Inspector may inspect at any stage.
    • The applicant must notify the Inspector for final inspection before underground portions are covered.
    • Inspection must occur within four hours for notice received in the forenoon and within eighteen hours for notice received in the afternoon.

    forenoon inspection response: <= 4 hours · afternoon inspection response: <= 18 hours

    “A permit for a private sewage disposal system shall not become effective until the installation is completed to the satisfaction of the Inspector. He/she shall be allowed to inspect the work at any stage of construction and, in any event, the applicant for the permit shall notify the Inspector when the work is ready for final inspection, and before any underground portions are covered.”
  • Mandatory utility hookupSewer (with conditions)

    Properties used for human occupancy, employment, recreation, or other purposes inside Southwest City town when a public or combined sewer is within 100 feet of the property line.

    • Connection must occur within 90 days after official notice.
    • If no public sewer is available under the city rule, a private sewage disposal system may be used subject to permit and inspection requirements.
    • A written city permit is required for a public-sewer connection.

    public sewer distance from property line: <= 100 feet · connection deadline after official notice: <= 90 days

    “The owner of all houses, buildings, or properties used for human occupancy, employment, recreation or other purposes, situated within the City and abutting any street, alley or right-of-way in which there is now located or may in the future be located a public sewer or combined sewer of the City, is hereby required, at his/her expense, to install suitable toilet facilities therein, and to connect such facilities directly with the proper public sewer in accordance with the provisions of this Chapter within ninety (90) days after date of official notice to do so, provided that said public sewer is within one hundred (100) feet of the property line.”

Rules another office applies inside Town of Southwest City

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

  • Minimum dwelling sizeSpecified

    R-1 Single-Family District inside Southwest City town.

    • The R-1 rule applies to single-family dwellings.
    • The dwelling cannot include a trailer house or mobile home.

    minimum living area: >= 1000 square feet

    “Single-family dwellings with a minimum of one thousand (1,000) square feet of living area. In no circumstances shall a single-family dwelling include a trailer house or mobile home.”
  • Lot coverageSpecified

    R-1 Single-Family District inside Southwest City town.

    • All buildings, including accessory buildings, are included in the coverage limit.
    • Detached accessory buildings not used as dwellings may be in the rear yard, must be at least five feet from side and rear lot lines, and may not be in a public easement.
    • Attached accessory buildings must meet principal-structure side and rear requirements.

    maximum lot coverage: <= 30 percent · detached accessory-building clearance: >= 5 feet (Side and rear lot lines.)

    “All buildings, including accessory buildings, shall not cover more than thirty percent (30%) of the area of the lot. Detached accessory buildings, not used as dwellings, can be located in the rear yard and shall have clearance of at least five (5) feet from side to rear lot lines and may not be located within a public easement.”
  • Building heightSpecified

    R-1 Single-Family District inside Southwest City town.

    • Basements are excluded from the story count.

    maximum stories: <= 2.5 stories (Basement excluded.) · maximum building height: <= 35 feet

    “Building Height. No building shall be erected or enlarged to exceed two and one-half (2 1/2) stories, excluding basement, or a maximum of thirty-five (35) feet.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Town of Southwest City or McDonald County directly.

  • Owner-builder exemption — Owner-builder exemptions inside Southwest City town.
  • Inspections — General building inspections inside Southwest City town.
  • Certificate of occupancy — Certificates of occupancy inside Southwest City town.
  • Living in an RV — Residential or long-term occupancy of recreational vehicles inside Southwest City town.
  • Camping on your land — Temporary camping inside Southwest City town.
6 more unanswered
  • Tiny homes
  • Accessory dwellings
  • Well permit
  • Agricultural exemption
  • Subdividing land
  • 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 Town of Southwest City publishes no rule on the point, not that none exists. McDonald County’s page lists the county offices to call.

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