Zoning, building permits and septic rules in Lexington Township, Kansas

Rules another office applies inside Lexington Township

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

• Building permitRequired

  Residential construction in unincorporated Johnson County, including Lexington township land outside cities

  • For residential buildings, a permit is required for any structure with floor area exceeding 200 sq. ft. (per the county page).
  • A permit is required to enlarge, alter, repair, move or demolish.
  • Address must show as 'unincorporated' in the county address search before applying; city addresses go to the city.

  residential detached structure floor area threshold: > 200 sq ft (Per the county page, any structure with floor area exceeding this threshold requires a permit; smaller structures are not listed as exempt in the text reviewed.)

  “for residential purpose, any structure with floor area exceeding 200 sq.' requires a permit.”

• Owner-builder exemptionConditional

  Owner doing own residential work in unincorporated Johnson County, including Lexington township land outside cities

  • The exemption from the county contractor licensing requirement applies only where the residence is for the use and occupancy of the homeowner only.
  • Homes built for sale or lease do not qualify.
  • Rental property: homeowners generally cannot pull permits.
  • Commercial projects must use a licensed general contractor; the owner cannot do the work.

  “in order to receive an exemption to the johnson county contractor licensing regulations, which requires the use of a licensed contractor to do the work, the residence must be for the use and occupancy of the homeowner only. it may not be built for sale or lease.”

• Building code adoptedAdopted

  New residential construction and remodels in unincorporated Johnson County, including Lexington township land outside cities

  • Cities in Johnson County enact their own building codes; those apply inside city limits.

  code edition: 2018

  “energy efficiency compliance submittal shall comply with johnson county code of regulations for buildings and construction 2018 edition and the 2018 international residential code, chapter 11”

• InspectionsRequired

  Permitted residential remodels and new construction in unincorporated Johnson County, including Lexington township land outside cities

  • Inspections are listed as applicable to the project type; the county notes the inspection schedule minimums.
  • If a septic or entrance permit is required, a final inspection report from Environmental and Public Works must be received before the final building inspection is scheduled.

  “note: if a septic or entrance permit were required, a final inspection report from environmental and public works must be received before schedule a final building inspection.”

• Local zoningPresent (with conditions)

  Land inside Lexington township that is outside incorporated cities: Johnson County's zoning and subdivision regulations apply there. This is county zoning, not an ordinance adopted by Lexington township.

  • The regulations apply only to unincorporated areas; land inside a city (for example Gardner or Olathe) is governed by that city.
  • The FAQ notes pockets of unincorporated land within some cities and towns where the regulations do apply.
  • The county is rewriting the regulations; the FAQ anticipated final adoption in July 2026, which this research did not confirm.

  “on march 17, 1994, the board of county commissioners adopted new zoning and subdivision regulations for the unincorporated area (that area not located in a city).”

• Zoning districtsPublished

  Zoning districts in unincorporated Johnson County, including Lexington township land outside cities

  • District names and standards are set in the county zoning and subdivision regulations, which the county says are being rewritten.
  • District-by-district tables were not opened.

  “different zones also often have different standards for the density of development or size and scale of buildings.”

• SetbacksDistrict specific (with conditions)

  Setbacks for structures on land inside Lexington township outside cities

  • Any structure regardless of size has setback requirements; contact the county planning department (913-715-2200) for the requirements for a given area.
  • Numeric setback distances by district were not retrieved.

  “any structure regardless of size has setback requirements, contact the planning department, 913-715-2200 or by email.”

• Accessory dwellingsLimited

  Accessory dwelling units on land inside Lexington township outside cities

  • The county lists two ADU application tracks: administrative review and public hearing required. The criteria that choose between them were not opened.
  • Zoning permit and inspection steps apply.

  “accessory dwelling unit – administrative review accessory dwelling unit – public hearing required”

• Who permits septicCounty (with conditions)

  Private septic systems on land inside Lexington township where no public wastewater collection system serves the property. The county schema allows only countywide for county authority; the rule applies inside Lexington township.

  • Johnson County Department of Health and Environment (JCDHE) runs the on-site sewage program; the county's Environmental Sanitary Code gives it authority.
  • Applies only where property is not served by a public wastewater collection system.

  “the residential on-site program issues permits for private sewage treatment systems where property owners are not served by a public wastewater collection system.”

• Septic permitRequired

  Private septic system work (repair, existing-system location checks, bedroom additions) on land inside Lexington township not served by public sewer

  • Repairs: contact a licensed installer; a JCDHE permit is required in most cases.
  • Where an existing system is present, a location check by Johnson County Environmental is required for a building permit.
  • If the project adds bedrooms, a permit from DHE may be required.
  • Contact JCDHE at 913-715-6900 for residential septic questions.

  “if repairs are needed, contact a licensed installer. a permit from jcdhe will be required in most cases.”

• Septic inspectionRequired

  New on-site septic systems and resale of homes served by private septic on land inside Lexington township

  • Resale inspection of an existing residential private system is required before a property is bought or sold; buyer or seller may request it.
  • New residential systems are inspected by the on-site program.

  “this is an inspection of the existing private sewage treatment system serving a residential property, which is required to be completed prior to a property being bought or sold.”

• Subdividing landRegulated (with conditions)

  Division of land inside Lexington township outside cities

  • Plats, lot splits and development plans require county approval under the county's zoning and subdivision regulations.
  • Buyers and sellers should check with the county planning office that resulting parcels meet minimum standards.

  “these regulations govern the subdivision of land and the types of land uses that are permitted in different zoning districts.”

• Driveway accessRequired

  New driveway or entrance on land inside Lexington township outside cities

  • Entrance permits are handled by Johnson County Public Works at 913-715-8300.
  • Required when this is the first structure on the property or when an additional entrance is added.

  “for an entrance permit (driveway) contact johnson county public works at 913-715-8300, if this is the 1st structure on your property or you are adding an additional entrance.”

• Building in a floodplainLimited

  Development on land inside Lexington township outside cities that lies in a mapped floodplain

  • A floodplain development permit is listed among county zoning permits; whether a given parcel is in a floodplain must be checked with county planning (913-715-2200).

  “floodplain development permit preliminary and final development plan application preliminary and final plat application”

• Short-term rentalsLimited

  Short-term rental of a dwelling on land inside Lexington township outside cities

  • A county short-term rental permit is required; its standards were not opened.

  “rezoning short-term rental permit sign permit special permit tract lot split zoning resources”

• Permit feesPublished

  Building and zoning permit fees for land inside Lexington township outside cities

  • Residential fees are due when the permit is issued, not when submitted.
  • Online payments by credit card carry a 2.4% service fee; American Express is not accepted.
  • Only the existence of a building permit fee chart link was seen; the fee amounts were not opened.

  “you can calculate your own or call for the fee amount, 913-715-2200.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Lexington Township or Johnson County directly.

• Certificate of occupancy — Certificate of occupancy for a new home in unincorporated Johnson County, including Lexington township
• Minimum dwelling size — Minimum dwelling size for a home on land inside Lexington township outside cities
• Minimum lot size — Minimum lot size for the main single-family residential district and agricultural or rural-residential district in unincorporated Johnson County, including Lexington township
• Lot coverage — Lot coverage limits for land inside Lexington township outside cities
• Building height — Maximum building height for land inside Lexington township outside cities

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.