Building permits, zoning and land rules in Johnson County, Tennessee

Unincorporated Johnson County, Tennessee does not require a county building permit for a new residential structure or addition¹. A project still needs septic and electric permits, and the county says it has a Certificate of Occupancy without explaining exactly when that certificate is required¹. Tennessee has adopted statewide building and fire-safety codes, but Johnson County opted its unincorporated area out of the state residential program^9,10. An owner or contractor may request State Fire Marshal inspection for a qualifying dwelling or addition, with a state Certificate of Occupancy issued if the inspected work meets statewide standards¹¹. Mountain City has its own municipal building code and permits³. New construction covered by the county flood process also needs a FEMA Flood Permit through the Property Assessor's Office⁷.

Johnson County does not issue a general building permit for new residential structures and additions in its unincorporated area¹. TDEC's Johnson City Environmental Field Office handles Johnson County septic applications and inspections^4,5. The Johnson County Property Assessor's Office accepts FEMA Flood Permit applications for new construction covered by the county process⁷. The county also requires an electric permit for new structures and additions, but we could not confirm a county construction-fee schedule¹. For a voluntary state inspection of a home in this opt-out jurisdiction, the owner or contractor obtains a state building permit through the State Fire Marshal's Office¹¹. Inside Mountain City, town permits cover listed structures over 200 square feet and attached exit-door decks of any size³.

Johnson County states that it has no Zoning Department, but that statement does not by itself confirm that every parcel lacks all land-use controls¹. Johnson County publishes subdivision regulations, and land divisions in the unincorporated county go through Planning Commission review¹². We could not confirm an unincorporated minimum dwelling size, minimum lot size, setback, lot-coverage limit or height limit, so ask county government about the parcel before dividing or developing it^1,12. Mountain City's zoning regulates uses and building and lot characteristics within town limits². Tennessee's county-zoning exemption for a farm structure requires agricultural land and a structure incidental to the farm enterprise; it excludes specified locations, including floodplains, and does not apply within municipalities¹³.

A new septic system or repair of a faulty system in Johnson County requires a Septic System Construction Permit before dirt work or construction begins⁵. Apply through TDEC's Johnson City Environmental Field Office, and have the installed system inspected before it is covered^4,5. A conventional-system permit costs $400 for design flow up to 1,000 gallons per day, while an alternative-system permit costs $500 at that flow; additional flow and construction inspection carry separate charges¹⁴. A repair permit has no permit fee, although its construction inspection costs $100¹⁴. Only 1.3% of Johnson County soils are rated without severe limits for a conventional drain field, so make septic feasibility an early purchase contingency¹⁵. Where soil or site conditions are unfavorable, Tennessee requires an Alternative Septic System Permit for systems such as mound or low-pressure pipe¹⁶. A qualifying sewer utility may require connection where a building's parcel abuts a public way containing its sanitary sewer¹⁷.

We could not confirm whether long-term RV occupancy or temporary camping is allowed on private land in unincorporated Johnson County, so ask county government before buying land for that use¹. Mountain City's travel-trailer-park rule limits a stay in the same park to 30 days, but it does not answer whether one RV may be occupied on an individual lot². In a Mountain City special flood-hazard area, an RV must stay fewer than 180 consecutive days, remain fully licensed and highway-ready, or meet all new-construction requirements¹⁸. A tiny home that meets Tennessee's ready-removable definition cannot be modified for residential, recreational or emergency housing¹⁹. Septic and electric permits still apply to new structures and additions in unincorporated Johnson County¹.

1. Confirm whether the parcel is inside Mountain City, because the town has separate zoning, building-code and permit rules^2,3.

1. Check the flood map and, when the county flood process applies, obtain the FEMA Flood Permit from the Property Assessor's Office⁷.

1. Have the site evaluated and obtain the septic construction permit before grading the building pad⁵.

1. Arrange the electric permit and ask county government when its Certificate of Occupancy applies, even though no county building permit is required¹.

1. Decide whether to request the optional state residential inspection route¹¹.

1. If the driveway enters a state highway right-of-way, obtain a TDOT permit before building or changing it²⁰.

1. In unincorporated Johnson County, an owner-builder needs no county building-permit exemption because no county building permit is required; state trade-licensing rules can still apply¹.

Start with septic feasibility: only 1.3% of Johnson County soils are rated without severe limits for a conventional drain field¹⁵. Terrain can sharply reduce practical building area because only 10.5% of county land is at a slope of 15% or less, while 81.9% is wooded¹⁵. Confirm legal access and obtain a TDOT permit if the driveway will connect to a state highway right-of-way²⁰. A proposed land split in unincorporated Johnson County goes through the county subdivision process¹². For a private well, hire a Tennessee-licensed driller and expect the driller to file the state report; we could not confirm a separate owner-issued county well permit⁸. Check flood status before closing because new construction covered by the county process requires a FEMA Flood Permit⁷.