Bolthole Index

Platte County, Missouri

Building permits, zoning and septic rules in Platte County, Missouri

48Index Score / 100
#111 of 115 in Missouri

Unincorporated Platte County, Missouri requires building permits for work covered by its building code, and Planning & Zoning enforces district zoning rules12. New homes need a Health Department septic permit or the applicable sewer-provider approval, plus water-availability documentation34. Occupancy requires a final inspection and certificate of occupancy5.

At a glance

Building permit
Required in unincorporated Platte County1
Zoning
Yes; district rules apply throughout unincorporated Platte County26
Septic permits
Required for new homes using onsite wastewater; sewer approval applies where service is available37
Owner-builder exemption
Not confirmed on county sources; ask Planning & Zoning8
Building codes
2018 building and residential codes, as amended910
Accessory dwelling
1 allowed in AG or RE on at least 5 acres with an existing principal home; conditions apply1112
Building inspections
Required at construction stages and before occupancy13
Private well
Landowners may install their own well or pump without an installer permit; confirm site requirements separately1415

Who to call

Building permits

Platte County Planning & Zoning Department

Building permits, inspections, and zoning administration (as Zoning Administrator) for unincorporated Platte County

816-858-3338

permits@co.platte.mo.us

415 Third Street, Suite 016, Platte City, MO 64079

Online permits →

Septic permits

Platte County Health Department (Environmental Health, Sewage Program)

Septic tank (onsite wastewater) permits for unincorporated Platte County

816-858-2412

Also useful

Platte County Regional Sewer District

Public sewer connection and sewer permits for parts of unincorporated Platte County that are not on septic; Timber Creek Sewer Company (816-858-3989) serves another area

816-858-2052

Contact details are copied from each office’s official page and were checked against it on October 13, 2026.

Off-grid gear

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Do you need a building permit in Platte County, Missouri?

Unincorporated Platte County, Missouri requires a building permit before covered construction, alteration, repair, moving, demolition or occupancy changes; ordinary repairs and certain portable-equipment connections are excepted1. Starting work before issuance can trigger doubled fees and a stop-work order, subject to the stated emergency exception1. Unincorporated Platte County uses amended 2018 building, residential, plumbing, mechanical, fuel-gas, energy-conservation and swimming-pool codes, plus the 2017 electrical code16109. For homes up to 1,400 square feet, the published building-permit fee is $200 for the first 500 square feet or part thereof, plus $.25 per additional square foot; larger homes use a different schedule1718. We could not confirm a general owner-builder exemption; ask Planning & Zoning819. City building permits come from Parkville20, Weatherby Lake21, Weston22, Lake Waukomis23, Dearborn24 inside their respective limits. Septic jurisdiction is separate: ask Platte County Health Department to confirm the authority for the address7.

Who is the Platte County building department, and how do you reach them?

Platte County Planning & Zoning handles building permits and zoning for unincorporated Platte County; call 816-858-3338 or email permits@co.platte.mo.us, or visit 415 Third Street, Suite 016, Platte City, Missouri19. Select “Building Permit Application” through a county website account and upload complete plans and supporting documents25; the packet states that review and action occur within 5 working days after all required information arrives26. Residential applications require septic or sewer documentation, a water-district availability letter and an entrance permit where applicable426. County building inspections cover footing, prebackfill, ground rough, rough-in and final stages13. Occupancy must wait for road and wastewater approvals, the required affidavit and a certificate of occupancy275.

Does Platte County have zoning in the unincorporated county?

Unincorporated Platte County has county-administered zoning, and a use that the parcel’s district does not authorize, or a special use without its approval, is prohibited6. Identify the parcel’s district on the Official Zoning Map filed with the County Clerk28229. Municipal zoning applies inside Parkville30, Platte City31, Riverside32, Weatherby Lake33, Weston34, Lake Waukomis35, Edgerton36, Dearborn37, Kansas City38, Smithville39; Kansas City reaches into Platte County mainly from Jackson County, and Smithville mainly from Clay County3839. Septic jurisdiction remains a separate address check with Platte County Health Department7. In Platte County’s AG district, dwellings generally need 100-foot front and rear yards and 30-foot side yards on interior lots; exceptions apply40. Other districts have their own area regulations, and in a planned residential development the setbacks are negotiated and recorded on the final plat before approval, then enforced41. In AG or RE, 1 accessory dwelling is allowed on at least 5 acres with an existing principal single-family home; the accessory dwelling cannot exceed the principal home’s floor area excluding its attached garage, must meet dwelling setbacks and share a driveway, and may need HOA approval1112.

What is the minimum lot size in Platte County?

Unincorporated Platte County’s principal-dwelling lot minimums include 40 acres in AG, 5 acres in RE, 80,000 square feet in R-80 and 40,000 in R-4042434445. Smaller residential districts have their own minimums and common-area provisions, so use the parcel’s actual classification4647484950. The RTD two-family district allows 5,000 square feet per dwelling unit, or 7,500 square feet for a single-family dwelling51, and the RMD multiple-dwelling district also sets 7,500 square feet for a single-family dwelling52. Ask Planning & Zoning about older-lot boundary-line exceptions and subdivision approval before dividing land or relying on a smaller tract425319.

How do septic permits work in Platte County?

Unincorporated Platte County construction using septic tanks requires a Platte County Health Department septic permit; public-sewer properties use the applicable sewer approval instead3. Call Environmental Health at 816-858-2412 for onsite permits, exemptions and inspections; the county ordinance may require more than Missouri’s minimum standards547. Residential sewer approval may come from Platte County Regional Sewer District or Timber Creek Sewer Company, depending on service55. The Regional Sewer District permit the county lists for commercial applications is a sewer connection permit, not approval of onsite septic systems56. About 11.9% of county soils are rated “not limited” by USDA for conventional drain fields; evaluate the site before placing the house, because a low share does not mean septic is impossible57. Inside Platte City, Riverside, Weston, Edgerton and Dearborn, city codes also require private-sewage permits and inspections while preserving additional health-authority requirements5859606162.

Can you live in an RV or tiny home on land in Platte County?

We could not confirm a general rule allowing long-term RV occupancy, temporary private-land camping or tiny-home occupancy in unincorporated Platte County; ask Planning & Zoning about the proposed unit, occupancy period and wastewater plan19. A mobile-home dwelling inside a regulated mobile-home park must have at least 500 square feet, excluding open porches, breezeways and garages; that threshold does not establish a countywide minimum home size63. Travel trailer camps need a Special Permit, are allowed only in AG and CH, and require at least 5 acres for short-term occupancy by the traveling public; those camp rules do not establish permission for household RV living on private land64.

What are the steps to build a home in Platte County?

  1. Confirm the district, allowed dwelling type, lot minimum and setbacks with Planning & Zoning6519.
  2. Establish the water and wastewater approval path, including the residential water-availability letter and septic or sewer permit4.
  3. Confirm the road authority and obtain an entrance permit where applicable; new entrances in unincorporated Public Works District #1 require a county entrance permit6626.
  4. Obtain a separate floodplain-development permit before development in a regulated flood zone67.
  5. Upload the complete online building application, plans and approvals, pay the building-permit fee, and wait for issuance before construction25171.
  6. Complete required inspections and driveway surfacing, then obtain the certificate of occupancy before moving in13685.

What should you check before buying land in Platte County?

Platte County reviews new plats and subdivisions for infrastructure, so ask Planning & Zoning about approval before buying a proposed land split5319. Driveways generally must match the accessed road surface and be at least gravel before occupancy; agricultural or single-family lots larger than 2 acres are excepted from matching unless the road-maintenance authority requires it68. Missouri permits landowners to install their own well or pump without an installer permit, but public wells need written approval and private-well requirements vary by category and location; confirm the water plan with Missouri DNR and county Planning & Zoning141519. Regulated flood-zone development requires separate approval and additional elevation, utility and sewage safeguards6769. Platte County's effective property-tax rate is about 1.1%, with a median annual bill near $3,3657071.

Watch-outs

  • Confirm whether your parcel needs a septic permit or approval from a sewer provider before designing the home site3.
  • We could not confirm a general owner-builder or agricultural exemption in Platte County; ask Planning & Zoning before assuming either removes building-permit requirements819.
  • A floodplain-development permit is separate from the building permit for work in regulated flood zones67.
  • Platte County Planning & Zoning's AG district requires at least 40 acres per dwelling, so a smaller AG-zoned parcel depends on a boundary-line exception or other relief; confirm the district before buying42.

Sources

  1. Planning And Zoning — Platte County, quoted and re-checked
  2. Platte County Zoning Order of 1990, quoted and re-checked
  3. Planning And Zoning — Platte County, quoted and re-checked
  4. Planning And Zoning — Platte County, quoted and re-checked
  5. Planning And Zoning — Platte County, quoted and re-checked
  6. Platte County Zoning Order, quoted and re-checked
  7. OWTS Construction Permit Process, quoted and re-checked
  8. (2026 county census)
  9. Building Permit Packet, quoted and re-checked
  10. Building Permit Packet, quoted and re-checked
  11. Platte County Zoning Order of 1990, quoted and re-checked
  12. Platte County Zoning Order, quoted and re-checked
  13. co.platte.mo.us, quoted and re-checked
  14. Missouri Water Well Guidance, quoted and re-checked
  15. Who Regulates Water Wells in Missouri?, quoted and re-checked
  16. Building Permit Packet, quoted and re-checked
  17. co.platte.mo.us, quoted and re-checked
  18. Planning And Zoning — Platte County, quoted and re-checked
  19. Platte County Planning & Zoning Department (co.platte.mo.us)
  20. Parkville: Chapter 500: Building Code (Platte County), quoted and re-checked
  21. Weatherby Lake: Article VI: Permits (Platte County), quoted and re-checked
  22. Weston: official source (Platte County), quoted and re-checked
  23. Lake Waukomis: Apply for a Building Permit and/or Business License (Platte County), quoted and re-checked
  24. Dearborn: Article VIII: Permits, Plats and Filing Fees and Culverts - City of Dearborn, MO (Platte County), quoted and re-checked
  25. Planning And Zoning — Platte County, quoted and re-checked
  26. Building Permit Packet, quoted and re-checked
  27. Planning And Zoning — Platte County, quoted and re-checked
  28. Platte County Zoning Order of 1990, quoted and re-checked
  29. Platte County Zoning Order of 1990, quoted and re-checked
  30. Parkville: City of Parkville, MO Code of Ordinances (Platte County), quoted and re-checked
  31. Platte City: Platte City, MO General Provisions (Platte County), quoted and re-checked
  32. Riverside: Code of Ordinances, City of Riverside, Missouri (Platte County), quoted and re-checked
  33. Weatherby Lake: Table of Contents - City of Weatherby Lake, MO (Platte County), quoted and re-checked
  34. Weston: Table of Contents - City of Weston, MO (Platte County), quoted and re-checked
  35. Lake Waukomis: Article II: One-Family Dwelling District A (Platte County), quoted and re-checked
  36. Edgerton: Chapter 405: Zoning Regulations - City of Edgerton, MO (Platte County), quoted and re-checked
  37. Dearborn: Table of Contents - City of Dearborn, MO (Platte County), quoted and re-checked
  38. Kansas City: Kansas City Zoning and Development Code, § 88-110-07, Infill Residential Development Standards (Platte County), quoted and re-checked
  39. Smithville: Code of Ordinances, City of Smithville, Missouri (Platte County), quoted and re-checked
  40. Platte County Zoning Order, quoted and re-checked
  41. Platte County Zoning Order, quoted and re-checked
  42. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  43. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  44. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  45. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  46. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  47. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  48. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  49. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  50. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  51. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  52. Platte County Zoning Order of 1990, as amended, quoted and re-checked
  53. Building Permit Packet, quoted and re-checked
  54. Platte County Health Department (Environmental Health, Sewage Program) (co.platte.mo.us)
  55. Planning And Zoning — Platte County, quoted and re-checked
  56. Platte County Planning & Zoning — Commercial Building Permit, quoted and re-checked
  57. 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
  58. Platte City: Article II: Wastewater Treatment Works (Platte County), quoted and re-checked
  59. Riverside: official source (Platte County), quoted and re-checked
  60. Weston: City of Weston, MO Public and Private Sewers (Platte County), quoted and re-checked
  61. Edgerton: Chapter 710: Sewers and Drainage - City of Edgerton, MO (Platte County), quoted and re-checked
  62. Dearborn: Chapter 710 Public and Private Sewers - City of Dearborn, MO (Platte County), quoted and re-checked
  63. co.platte.mo.us, quoted and re-checked
  64. Platte County Zoning Order, Chapter 400, quoted and re-checked
  65. Platte County Zoning Order, quoted and re-checked
  66. Driveway and Culvert Policy, quoted and re-checked
  67. Chapter 410 Floodplain Management Ordinance, quoted and re-checked
  68. Building Inspection Requirements, quoted and re-checked
  69. Flood Plain Management Ordinance, quoted and re-checked
  70. Effective property tax rate: Bolthole Index county data
  71. Median property tax bill: Bolthole Index county data

Written October 13, 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.

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Compared with neighboring counties

Like 5 of its 6 neighbors, Platte County requires a building permit for a home.

RulePlatte CountyClay CountyBuchanan CountyClinton CountyJackson CountyRay CountyAndrew County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredNot required
County zoningYesYesYesYesYesYesNo
Septic permitsCounty Health Dept.County Public Health CenterCounty Planning & ZoningCounty Health Dept.County Public Works On-Site Wastewater programCounty Health Dept. Env. HealthCounty Health Dept.

County locator

Platte County in Missouri

48
County map
Platte County highlighted among the Missouri counties · colored by Index score

How Platte County scores

Seclusion20100% ev.
Self-Sufficiency63100% ev.
Admin Boringness4690% ev.
Durability61100% ev.
Property Autonomy47100% ev.
Carry Cost70100% ev.

Evidence strength: 98%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$396kTypical home
1.1%Property tax
$5,713Land / acre
38.6"Annual rain
7.3% of yrsSevere drought
15.9 / yr (+13)Mid-century 100°F days
20.2 daysMid-century dry spell
2.34" (+6.2%)Mid-century 1-day rain
1.66×Wildfire change factor
100%Forward climate coverage
$2,269Home insurance / yr
3.6% / yrInsurance growth
1.27%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
209,692People within 30 min
3,112,666People within 2 hr
259,969Radius comparison (15 mi)
266.6People / sq mi
0.4%Federal land
83.6%Land at 15% slope or less
11.9%Soils rated "not limited" for septic (strict USDA rating)
31,365 acWorkable land screen
35.7%Wooded land
44.6 tonsBiomass / forest ac
54.7°FAvg temp

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Cities and towns in Platte County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Not yet researched: Camden Point · Village of Farley · Village of Ferrelview · Houston Lake · Village of Iatan · Platte Woods · Village of Ridgely · Tracy

Answers from the rulebook for Platte County

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

Platte County rules

  • Building permitRequired

    Construction, alteration, repair, moving, demolition, or occupancy changes covered by the county building code.

    • Ordinary repairs and certain portable-equipment connections are excepted as stated in the source.
    • Construction may not begin until the permit is issued.
    • The county page states that work started before a permit may trigger doubled fees and a stop-work order, except in emergency situations determined by the Building Official or Zoning Enforcement Officer.
    “Any owner or owner’s authorized agent who intends to construct, enlarge, alter, repair, move, demolish or change the occupancy of a building or structure [...] shall first make application to the building official and obtain the required permit.”
  • Building code adoptedAdopted (with conditions)

    County-administered building and specialty codes for construction regulated by Platte County.

    • The listed codes are adopted as amended.
    • The packet also lists the 2017 National Electrical Code and ICC 700-2008.

    International Building Code: 2018 version as amended · International Residential Code: 2018 version as amended

    “International Building Code 2018 version (as amended)”
    2 more reviewed findings on this topic
    • Adopted — County building and specialty codes administered by Platte County.
      “BUILDING AND SPECIALTY CODES ADOPTED BY PLATTE COUNTY, MISSOURI:”
    • Adopted — County-regulated construction in Platte County.
      “International Building Code 2018 version”
  • InspectionsRequired

    County-permitted construction inspections, including staged inspections and final inspection.

    • Inspections cover various construction stages and final approval is needed before occupancy.
    • Specific inspection requirements vary by project.
    “Inspections: Conducting field inspections for various stages of construction (footing, prebackfill, ground rough, rough-in (framing, electrical, plumbing, mechanical), and final) to ensure code adherence.”
    One more reviewed finding on this topic
    • Required — Permitted building construction in unincorporated Platte County.
      “Final:Inspected before occupancy of the structure. This inspection occurs after all permitted construction is complete, before occupancy, and verifies life safety, fire safety, structural integrity, and compliance with all approved plans for electrical, plumbing, mechanical, and building aspects.”
  • Certificate of occupancyRequired

    Structures subject to county building-permit administration before occupancy.

    • Final inspection must approve the structure and site plan.
    • A notarized affidavit and required approvals from the appropriate road district, sewer district, or health department, plus other necessary documentation, must be submitted.
    • A temporary certificate may be issued only for exterior items, with the interior complete, for one six-month period when due cause is shown and approved.

    temporary certificate period: 6 months (one time period)

    “Upon approval of the final inspection (when it is found that the building or structure and site plan complies with ALL CODE provisions of Platte County) and following submission of the notarized affidavit, required approvals from the appropriate road district, sewer district, or health department and any other documentation necessary for this structure, the building Official will issue a certificate of occupancy (CO).”
  • County-wide zoningPresent (with conditions)

    Land-use regulation under the Platte County Zoning Order in the county's unincorporated jurisdiction.

    • The source establishes comprehensive county zoning regulations and district-based controls.
    • Incorporated municipalities may impose their own municipal zoning rules.
    “The County Commission of Platte County, Missouri, hereby adopts and enacts these comprehensive zoning regulations.”
    One more reviewed finding on this topic
    • Present — County zoning regulations in the unincorporated area of Platte County.
      “Except as hereinafter otherwise provided, no land shall be used and no building, structure or improvement shall be made, erected, constructed, moved, altered, enlarged or rebuilt which is designed, arranged or intended to be used or maintained for any purpose or in any manner except in accordance with the requirements established in the district in which such land, building, structure or improvement is located”
  • Local zoningPresent

    Land, buildings, structures, and improvements regulated by the Platte County Zoning Order.

    • The order regulates uses according to the applicable zoning district.
    • Uses not authorized by the specific district regulations, or special uses without necessary approval, are prohibited.
    “The County Commission of Platte County, Missouri, hereby adopts and enacts these comprehensive zoning regulations.”
    One more reviewed finding on this topic
    • Present — County-administered zoning in unincorporated Platte County.
      “Platte County is hereby divided into zones as shown on the Official Zoning Map, consisting of some forty-one (41) individual map sheets, filed with the County Clerk.”
  • Zoning districtsPublished

    County zoning districts in Platte County.

    • The zoning map consists of approximately forty-one individual map sheets filed with the County Clerk.
    • District-specific requirements apply to land and structures.

    official zoning map sheets: 41 map sheets

    “Platte County is hereby divided into zones as shown on the Official Zoning Map, consisting of some forty-one (41) individual map sheets, filed with the County Clerk.”
    One more reviewed finding on this topic
    • Published — County zoning districts and district-specific regulations in unincorporated Platte County.
      “Upon such approval, the letters "PR" shall be affixed to the appropriate part of the county's official zoning district map.”
  • Minimum dwelling sizeDistrict specific (with conditions)

    Mobile-home dwellings in county-regulated mobile-home parks.

    • The source-specific minimum applies to mobile-home park sites and does not establish a countywide minimum for all dwellings.

    minimum floor area: >= 500 square feet (excluding open porches, breezeways and garages)

    “No mobile home dwelling unit shall be allowed in a mobile home park unless it has a minimum floor area of five hundred (500) square feet measured by outside dimensions”
  • Minimum lot sizeDistrict specific (with conditions)

    Residential dwelling units in the RMD Residential Multiple Dwelling District in unincorporated Platte County.

    • For three town houses or multiple-family dwelling units, the minimum is per dwelling unit.
    • For buildings other than single-family, two-family, and three-family dwellings, the minimum is 13,000 square feet for the first four dwelling units plus 2,500 square feet for each dwelling unit above four, including private and common area; common area is allocated equally per dwelling unit.
    • A boundary-line exception permits one single-family dwelling where all boundary lines touch lands under other ownership at the effective date of the Order.

    single-family minimum lot area: >= 7500 square feet (Single dwelling unit with a common party wall may have 2,500 square feet.) · two-family minimum lot area: >= 5000 square feet per dwelling unit · three-unit town house or multiple-family minimum: >= 3500 square feet per dwelling unit · other multiple-family minimum: >= 13000 square feet for first four dwelling units (Plus 2,500 square feet for each dwelling unit above four.)

    “For each single-family dwelling and building accessory thereto, there shall be a lot area of not less than seven thousand five hundred (7,500) square feet. For a single dwelling unit with a common party wall there shall be a lot area of not less than two thousand five hundred (2,500) square feet. For each two-family dwelling and building accessory thereto, there shall be a lot area of not less than five thousand (5,000) square feet per dwelling unit.”
    10 more reviewed findings on this topic
    • District specific (with conditions) — Each dwelling and building accessory thereto in the R-25 Single-Family Large Lot District in unincorporated Platte County.
      “For each dwelling and building accessory thereto, there shall be a lot area not less than twenty-five thousand (25,000) square feet, except that the lot area may be no less than twenty thousand (20,000) square feet when five thousand (5,000) additional square feet of accessible common area is provided in the subdivision as required by the Subdivision Regulations.”
    • District specific (with conditions) — Each dwelling and building accessory thereto in the AG Agricultural District in unincorporated Platte County.
      “For each dwelling and building accessory thereto, there shall be a lot area of not less than forty (40) acres.”
    • District specific (with conditions) — Each dwelling and building accessory thereto in the RE Rural Estates District in unincorporated Platte County.
      “For each dwelling and building accessory thereto, there shall be a lot area of not less than five (5) acres.”
    • District specific (with conditions) — Each dwelling and building accessory thereto in the R-80 Rural Single-Family District in unincorporated Platte County.
      “For each dwelling and building accessory thereto, there shall be a lot area of not less than eighty thousand (80,000) square feet.”
    • District specific (with conditions) — Each dwelling and building accessory thereto in the R-40 Single-Family Estate District in unincorporated Platte County.
      “For each dwelling and building accessory thereto, there shall be a lot area of not less than forty thousand (40,000) square feet.”
    • District specific (with conditions) — Each dwelling and building accessory thereto in the R-15 Single-Family Low Density District in unincorporated Platte County.
      “For each dwelling and building accessory thereto, there shall be a lot area of not less than fifteen thousand (15,000) square feet, except that the lot area may be no less than twelve thousand (12,000) square feet when three thousand (3,000) additional square feet of accessible common area is provided in the subdivision as required by the Subdivision Regulations.”
    • District specific (with conditions) — Each dwelling and building accessory thereto in the R-12 Single-Family Medium Density District in unincorporated Platte County.
      “For each dwelling and building accessory thereto, there shall be a lot area of not less than twelve thousand (12,000) square feet, except that the lot area may be no less than ten thousand (10,000) square feet when two thousand (2,000) additional square feet of accessible common area is provided in the subdivision as required by the Subdivision Regulations.”
    • District specific (with conditions) — Each single-family dwelling and building accessory thereto in the R-10 Single-Family Medium-High Density District in unincorporated Platte County.
      “For each single-family dwelling and building accessory thereto, there shall be a lot area of not less than ten thousand (10,000) square feet, except that the lot area may be no less than nine thousand (9,000) square feet when one thousand (1,000) additional square feet of accessible common area is provided in the subdivision as required by the Subdivision Regulations.”
    • District specific (with conditions) — Each dwelling and building accessory thereto in the R-7 Single-Family High Density District in unincorporated Platte County.
      “For each dwelling and building accessory thereto, there shall be a lot area of not less than seven thousand five hundred (7,500) square feet, except that the lot area may be no less than seven thousand (7,000) square feet when five hundred (500) additional square feet of accessible common area is provided in the subdivision as required by the Subdivision Regulations.”
    • District specific (with conditions) — Dwelling units in the RTD Two-Family Residential District in unincorporated Platte County.
      “For each two-family dwelling and building accessory thereto, there shall be a lot area of not less than five thousand (5,000) square feet per dwelling unit. For each single-family dwelling and building accessory thereto, there shall be a lot area of not less than seven thousand five hundred (7,500) square feet.”
  • SetbacksSpecified

    Buildings and dwellings in the county's AG Agricultural zoning district under the Platte County Zoning Order.

    • The cited measurements apply specifically to the AG district and should not be generalized to other zoning districts.
    • Double-frontage lots must provide the front-yard requirement on both streets.
    • Interior-lot dwellings require a side yard on each side; corner lots require a 75-foot setback from the intersecting street.
    • Accessory buildings other than dwellings require 100-foot side setbacks.
    • Accessory buildings have a 50-foot rear yard requirement.
    • Article III Section 400.330 may provide exceptions to the 30-foot interior-lot side-yard rule.

    front yard minimum depth: >= 100 feet (double-frontage lots must provide the requirement on both streets) · interior-lot dwelling side yard: >= 30 feet (except as provided in Article III, Section 400.330) · corner-lot setback from intersecting street: >= 75 feet · accessory-building side yard: >= 100 feet (accessory buildings other than dwellings) · dwelling rear yard: >= 100 feet · unattached accessory-building rear yard: >= 50 feet

    “SECTION 400.130 "AG" AGRICULTURAL DISTRICT [...] The minimum depth of the front yard shall be one hundred (100) feet. [...] For dwellings located on interior lots, there shall be a side yard on each side of the main building of not less than thirty (30) feet, except as hereinafter provided in Article III, Section 400.330. For dwellings located on corner lots, there shall be a side yard setback from the intersecting street of not less than seventy-five (75) feet. [...] For accessory buildings other than dwellings, there shall be a side yard setback from all exterior and interior side lot lines of not less than one hundred (100) feet. [...] There shall be a rear yard for dwellings of not less than one hundred (100) feet. For unattached buildings of accessory use to dwellings, there shall be a rear yard of not less than fifty (50) feet.”
    One more reviewed finding on this topic
    • Specified — Setbacks in county zoning districts and planned residential developments.
      “The lot width, front yard, side yard and rear yard setbacks are to be negotiated and established before final plat approval. The area regulations must be recorded on the final plat. Once the setbacks for a Planned Residential Development are recorded, they will be enforced.”
  • Living in an RVLimited

    Travel trailer camp occupancy in unincorporated Platte County.

    • Requires a Special Permit under Article VIII, Section 400.760.
    • The zoning order permits this use in AG and CH districts only.
    • The minimum tract size is five acres in one ownership.
    • The tract must be primarily designated for short-term occupancy by the traveling public.
    • Maximum density is twenty travel-trailer spaces per acre.
    • Each trailer space must be at least twenty-five feet wide; trailers must be at least ten feet from adjacent units, structures, or roadways and at least thirty feet from development property lines.
    • Additional requirements may be imposed as conditions of approval to protect public health, safety, and general welfare.

    minimum tract size: >= 5 acres (must be in one ownership) · maximum travel trailer spaces: <= 20 per acre · minimum trailer space width: >= 25 feet · minimum separation from adjacent unit, structure, or roadway: >= 10 feet · minimum separation from development property lines: >= 30 feet

    “Travel trailer camps may be approved by Special Permit in Districts "AG" and "CH"”
  • Accessory dwellingsLimited

    Accessory dwellings in county zoning districts where permitted.

    • Accessory dwellings are permitted in AG and RE zoning classifications.
    • One accessory dwelling is permitted per parcel in addition to the existing principal single-family dwelling.
    • In AG and RE, the minimum lot size is five acres and the accessory dwelling cannot exceed the square footage of the existing principal single-family dwelling, excluding an attached garage.
    • The accessory dwelling must meet applicable setbacks, share one driveway with the principal dwelling, and may require homeowners-association approval.

    maximum accessory dwellings per parcel: 1 (in addition to existing principal single-family dwelling) · minimum lot size: >= 5 acres (AG and RE districts)

    ““AG” (Agricultural) and “RE” (Rural Estates)”
    One more reviewed finding on this topic
    • Allowed (with conditions) — One accessory dwelling on a parcel with an existing principal single-family dwelling in the AG or RE zoning districts.
      “An Accessory Dwelling shall be a Permitted Use in the following zoning classifications: “AG” (Agricultural) and “RE” (Rural Estates).”
  • Who permits septicLocal (with conditions)

    Onsite wastewater permitting under Platte County's onsite wastewater ordinance, including unincorporated Platte County.

    • The Missouri Department of Health and Senior Services identifies Platte County Health Department as the authority under a county ordinance.
    • The county has its own onsite wastewater ordinance and may impose requirements beyond state minimum standards.
    • For work in incorporated cities that do not fall under the local permitting authority, the permitting process may defer to DHSS.
    • For unincorporated Platte County installations, the Health Department page states that the homeowner must obtain a permit and that Environmental Health issues permits and permit exemptions and performs inspections.
    “Agency: Platte County Health Dept. Authority Type: Ordinance [...] Contact the agency above for onsite wastewater permitting instructions. This county has their own Onsite Wastewater Ordinance and may have additional requirements beyond the state minimum construction standards. Some cities in Missouri are incorporated and may not fall under the local permitting authority even when an ordinance is in place. If work is being done within one of these incorporated areas, the local permitting authority will defer the permit process back to DHSS.”
    One more reviewed finding on this topic
  • Septic permitRequired

    Residential and commercial construction requiring onsite sewage disposal or septic tanks in the county permitting jurisdiction.

    • The required approving entity varies by property: Platte County Health Department, Platte County Regional Sewer District, or Timber Creek Sewer Company.
    • A sewer permit is used where public sewer applies.
    “Septic tanks, if applicable, require a permit from the Platte County Health Department.”
    One more reviewed finding on this topic
    • Required — New one- or two-family dwelling construction using onsite wastewater in unincorporated Platte County.
      “Septic or sewer permit from the Platte County Health Department (816-858-2412), Platte County Regional Sewer District (816-858-2052), or Timber Creek Sewer Company (816-858-3989).”
  • Mandatory utility hookupConditional

    New residential and commercial construction requiring water or wastewater service approvals.

    • Residential applications require a septic or sewer permit and an approval letter from the appropriate water district stating water is available.
    • Commercial applications require the applicable septic/sewer, water-district, and, if required, road-district or Missouri Department of Transportation approvals.
    “An approval letter from the appropriate water district stating water is available.”
  • Subdividing landRegulated (with conditions)

    Subdivision and plat review under Platte County Planning and Zoning and the county subdivision regulations.

    • The county building packet lists Platte County Subdivision Regulations, adopted in 1992 as amended.
    • The county planning page describes subdivision review and approval of new plats and subdivisions, including infrastructure review.
    “Subdivision Review: Approving new plats and subdivisions, ensuring proper infrastructure (roads, utilities).”
  • Driveway accessRequired

    Parking areas, dwellings, garages, and carports subject to county zoning requirements.

    • Driveway or parking surfaces must be ready before certificate of occupancy.
    • The surface generally must match the accessed road surface; at minimum it must be gravel.
    • Lots larger than two acres used for agricultural or single-family residential purposes are excepted from the matching-surface rule unless the road-maintenance entity specifies otherwise.
    • One- and two-family dwelling parking areas or customary driveways in required yards abutting streets are limited to 35 percent of those yards.

    large-lot threshold: > 2 acres (agricultural or single-family residential lots under the cited rule)

    “All parking areas, dwellings, garages and carports shall be accessed by a driveway.”
    One more reviewed finding on this topic
    • Limited — New entrances to property in the unincorporated part of Platte County in Public Works District #1.
      “All residents, commercial businesses, farming operations etc. that wish to install a new entrance to a property in the unincorporated part of Platte County in District #1, must first apply for an Entrance Permit through the Department of Public Works and pay a $75.00 permit fee that is good for one (1) year. Should the permit expire prior to getting the entrance installed, a renewal fee of $5.00 will be required to reinstate the permit for an additional one (1) year.”
  • Building in a floodplainLimited

    New construction, substantial improvements, other improvements, subdivision proposals, and manufactured-home placement in designated flood hazard zones.

    • No floodplain-development permit may be granted in numbered or unnumbered A, AE, AO, or AH zones unless the ordinance conditions are satisfied.
    • Until a floodway is designated, development in numbered A or AE zones requires demonstration that cumulative effects will not increase base-flood water surface elevation by more than one foot at any point in the community.
    • New construction and other development must satisfy anchorage, flood-resistant materials, flood-damage-minimization, utility, sewage, and subdivision requirements.

    maximum cumulative base-flood elevation increase before floodway designation: <= 1 foot (at any point in the community)

    “No permit for floodplain development shall be granted for new construction, substantial improvements, and other improvements”
    One more reviewed finding on this topic
    • Required — Construction or other development in Platte County numbered or unnumbered A zones and AE zones identified in the county flood-insurance mapping provisions.
      “In all areas covered by this ordinance, no development shall be permitted except through the issuance of a floodplain development permit”
  • Permit feesPublished (with conditions)

    County building permits and listed permit types.

    • Residential one- and two-family fees vary by square footage.
    • Commercial fees are $500 for the first $5,000 of estimated cost plus $25 for each additional $5,000.
    • Electrical or mechanical permits cost $50; demolition fees are $25 residential and $100 commercial; sign permits cost $75; deck permits cost $50; swimming-pool permits cost $75.
    • A permit started before issuance may have a doubled fee except in emergency situations.

    commercial building permit first $5000: 500 USD (plus $25 for each additional $5,000 of estimated cost) · electrical or mechanical permit: 50 USD · residential demolition permit: 25 USD · commercial demolition permit: 100 USD

    “Up to 1,400 square feet: $200.00 for the first 500 square feet, or part thereof, plus $.25 for each additional square foot after the first 500 square feet.”
    One more reviewed finding on this topic
    • Published (with conditions) — County building permits and related permit types listed on the official Planning and Zoning page.
      “Up to 1,400 square feet: $200.00 for the first 500 square feet, or part thereof, plus $.25 for each additional square foot after the first 500 square feet.”
  • Permit processPublished (with conditions)

    County building-permit applications.

    • Applications are submitted online through the county website after creating or accessing an account.
    • All required information and building plans must be presented in their entirety.
    • Plans are reviewed in the order received after required documents are uploaded.
    • Residential applications require septic/sewer documentation, water availability approval, and an entrance permit where applicable.

    application review period: <= 5 working days (after receipt of all required information)

    “A building permit application shall be reviewed and acted upon within five (5) working days after the receipt of all the required information.”
    One more reviewed finding on this topic
    • Published (with conditions) — County building-permit application process in unincorporated Platte County.
      “Select ‘Building Permit Application’ and fill out the online form.”

Missouri rules that apply here

  • 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.”
    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.”
  • 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.”
    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).”
  • Well permitLimited

    Construction or alteration of a public well serving a Missouri public water system.

    • Public water systems must receive written approval from the Missouri Department of Natural Resources Public Drinking Water Branch before constructing or altering a public well.
    • The requirement does not apply when the system meets the charitable-and-benevolent-organization exemptions in section 640.116, RSMo.
    • Anyone proposing to install a public well must contact the department’s regional office for a well-site survey.
    • The survey addresses minimum isolation or setback distances from known or potential contaminant sources, including septic tanks, sanitary sewer lines, and landfills.
    • Before applying for construction authorization, the public water system must obtain an estimated casing-depth letter from the Missouri Geological Survey Water Resources Center.
    • There is no fee for the well-site-survey and estimated-casing-depth-letter services.
    • Failure to obtain construction authorization may result in approval delays and possibly require the owner to properly plug the well and drill a new one according to 10 CSR 60-3.

    public water system threshold: at least 15 service connections or regularly serves an average of at least 25 individuals daily, at least 60 days per calendar year

    “Public water systems must receive written approval from the PDWB before constructing or altering a public well”
    4 more reviewed findings on this topic
    • Limited — Water wells in Missouri, including Platte County.
      “Public water systems must receive written approval from the PDWB before constructing or altering a public well, unless the system meets the charitable and benevolent organization exemptions in section 640.116, RSMo.”
    • Limited — Water-well construction, repair, pump installation, and contracted well work applicable in Platte County.
      “A restricted water well or pump installation permit is required for someone to contract these activities or to direct the installation. Landowners may install their own well or pump without a permit pursuant to the above mentioned law and rules.”
    • Required — 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.
      “A non-restricted permit is required to drill, construct, repair, reconstruct, plug, or install pumps or pumping equipment in a well.”
    • Limited — Construction or repair of water wells, installation or replacement of pumps, and associated plumbing and electrical work in Missouri.
      “A non-restricted water well installation permit is required to construct or repair a water well in Missouri.”
  • Agricultural exemptionAvailable (with conditions)

    Farm buildings and farm structures used for agricultural purposes under the county building and land-use restriction provisions of RSMo sections 64.800 to 64.905.

    • The exemption does not apply within incorporated portions of counties.
    • The exemption applies to raising crops, livestock, orchards, or forestry and to specified rice-farming or flood-irrigation impoundments.
    • For farm buildings or farm structures, the area must not be within the area shown on the flood hazard area map.
    • The statute preserves the validity of county ordinances or orders adopted before March 4, 1991.
    • Other laws and local requirements may still apply.

    rice-farming or flood-irrigation berm height: <= 18 inches (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 in an area not within the area shown on the flood hazard area map.”
    4 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.”
    • Available (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.
      “This section shall not apply to the erection, maintenance, repair, alteration or extension of farm buildings or farm structures used for such purposes [...]”
    • 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 [...]”
    • Available — Erection, maintenance, repair, alteration, or extension of farm buildings or farm structures with respect to 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.”
  • 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.”
    2 more reviewed findings on this topic
  • 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”
    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”
    • 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”

Still unanswered

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

  • Owner-builder exemption — Owner-builder exemption from county building permit or code requirements.
  • Lot coverage — General county zoning lot-coverage requirements.
  • Camping on your land — Temporary camping on private land in unincorporated Platte County.
  • Tiny homes — Tiny-home occupancy in unincorporated Platte County.
  • Manufactured homes — Manufactured-home occupancy outside a regulated mobile-home park in unincorporated Platte County.
1 more unanswered
  • 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.

Living off-grid in Platte County, Missouri

Is Platte County a good place to live off-grid or homestead?

Platte County scores 48/100 on the Bolthole Index, a solid county profile. Its strengths: manageable long-term carry cost and workable self-sufficiency basics (38.6″/yr rainfall). Watch-outs: about 209,692 people within a 30-minute drive.

Do you need a building permit in Platte County, Missouri?

Platte County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Platte County Health Department, Environmental Health (Sewage Program). 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.

Can you live in an RV or tiny home on your land in Platte County?

Living in an RV on your own land in Platte County is limited to specific cases: Travel trailer camp occupancy in unincorporated Platte County. Requires a Special Permit under Article VIII, Section 400.760. The zoning order permits this use in AG and CH districts only. Confirm with the county before relying on it.

How much does land cost in Platte County, Missouri?

Land in Platte County runs about $5,713 per acre, based on the latest county data.

What is the water situation in Platte County?

Platte County gets about 38.6" of rain a year, with severe drought in roughly 7.3% of years.

How remote is Platte County?

A representative private-land location has about 209,692 people within a 30-minute drive and 3,112,666 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.

How Platte compares in Missouri

Compare side-by-side →See all 115 Missouri counties ranked →