Bolthole Index

Union County, Tennessee

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

73Index Score / 100
#40 of 95 in Tennessee

Union County, Tennessee requires a building permit, and the county Assessor of Property sells permits for new construction in person rather than online.12 Union County also has zoning, but parcel-specific zoning and building-code details should be confirmed before buying or designing.3 Septic permits and inspections are handled by TDEC's Knoxville Environmental Field Office.45

At a glance

Building permit
Required; purchase it in person from the Union County Assessor of Property12
Zoning
Yes; confirm the parcel's district and allowed use with Union County before designing3
Septic permit
Required for a new system or repair and administered by TDEC46
Owner-builder
Allowed for a personal residence, subject to Tennessee's conditions78
RV living
Not confirmed; ask the county about the parcel and intended length of stay3
Tiny home
Not confirmed; ask the county about zoning, minimum size and occupancy approval3
Septic soil difficulty
Only about 11.4% of soils lack severe limits for a conventional drain field9
Property tax
Effective rate about 0.4%; median annual bill about $7201011

Who to call

Building permits

Union County Assessor of Property

Building permits and 911 addresses for new construction in Union County

865-992-3211

[email protected]

901 Main Street, Suite 106, Maynardville, TN 37807

Septic permits

TDEC Knoxville Environmental Field Office

Septic-related inquiries, applications and inspection coordination for Union County

(865) 594-6035

3711 Middlebrook Pike, Suite 101, Knoxville, TN 37921

Online permits →

Contact details are copied from each office’s official page and were checked against it on September 27, 2026.

Do you need a building permit in Union County, Tennessee?

Yes. Union County requires building permits, and the Assessor of Property says every county building permit must be purchased in that office.12 The office sells permits for new construction, assigns 911 addresses for new construction, and does not offer its building permits online.2

The available information does not establish which locally adopted building code applies, what inspections follow, or whether a certificate of occupancy is required. Ask the Assessor of Property to identify the current code official, required inspections, permit fee and closeout documents for the exact project before work begins. Tennessee's state residential permit requirement applies only where the state administers that program, while local governments remain responsible for locally adopted codes and other approvals.12

Who issues Union County building permits, and how do you reach the office?

The Union County Assessor of Property is the practical first stop for a house or other new construction because the office sells the county's building permits and assigns new-construction 911 addresses.2 Visit the Assessor of Property at 901 Main Street, Suite 106, Maynardville, or call the published office number before making the trip.2 Permits are not offered online.2

Ask the office what plans and site documents to bring, how the fee is calculated, which inspections apply, and who reviews zoning. Union County's published information confirms the permit-sales role, but we could not confirm a separate county building department, inspection schedule or current fee schedule. The distinction matters because Tennessee's state residential program does not replace local zoning, septic, floodplain, grading or electrical approvals.12

Does Union County, Tennessee have zoning?

Union County has adopted zoning and subdivision regulations, so rural land should not be treated as unrestricted.3 Tennessee law allows counties to zone land outside municipal corporations, while incorporated places may administer their own rules.13 Before relying on a listing or a seller's description, ask Union County which jurisdiction and zoning district cover the parcel and whether the proposed dwelling, accessory building or business use is allowed.

We could not confirm a current official district schedule for setbacks, minimum dwelling size, minimum lot size, lot coverage or building height. Ask for a written zoning determination tied to the parcel, particularly for a tiny home, manufactured home, accessory dwelling or long-term RV use. A qualifying agricultural structure may receive protection from county zoning only when it is on land devoted to agricultural use and incidental to the agricultural enterprise, subject to stated location and floodplain exceptions.14

How do septic permits work in Union County?

TDEC administers septic permitting for Union County through the Knoxville Environmental Field Office.155 A Septic System Construction Permit is required before installing a subsurface system or repairing a faulty one.6 Obtain that approval before dirt work or construction begins, including preparation of a building pad.16

TDEC evaluates the site and may request a site plan, soil map or engineered design; processing can take up to 45 days after a complete application arrives.17 The installer must arrange the final inspection before covering the system, and TDEC issues a Certificate of Completion after approval.18 Only about 11.4% of Union County soils lack severe limits for a conventional drain field, so make septic feasibility an early purchase contingency rather than assuming a conventional layout will work.9 Electrical-service processing also requires written notice of public sewer service, a septic application or use of an existing system.19

Can you live in an RV or tiny home in Union County?

We could not confirm a Union County rule that allows or prohibits living in an RV on private land, temporary camping, tiny-home occupancy, manufactured-home occupancy or accessory dwellings. Because Union County has zoning, a small structure or vehicle is not automatically approved as a residence merely because the land is rural.3 Ask the county for a parcel-specific answer covering the proposed use, duration, utility connections, setbacks and any required occupancy approval.

A tiny home used as a dwelling still needs a workable sanitation path: installation of a septic system or repair of a faulty system requires a TDEC construction permit.6 For an owner-built conventional residence, Tennessee allows a property owner to build one personal-use home under the owner-builder conditions, but the home cannot be intended for sale, lease or rent.8 That contractor-licensing exception does not itself settle zoning, building-code, septic or RV-occupancy questions.

Building a home in Union County: what are the steps?

  1. Ask Union County to confirm the parcel's jurisdiction, zoning district, allowed dwelling type and dimensional standards; the county has zoning, but the current parcel-level standards were not confirmed.3
  2. Establish septic feasibility and apply through TDEC before grading or preparing the building pad; a septic construction permit is required for a new system or repair.16
  3. Obtain the 911 address and purchase the Union County building permit in person from the Assessor of Property.2
  4. Ask which locally required inspections and electrical approvals apply; electrical-service processing requires sewer or septic documentation.19
  5. If the driveway connects to a Tennessee state highway right-of-way, obtain the required TDOT highway entrance permit before constructing or changing it.20
  6. Have the septic installer schedule TDEC's final inspection before covering the system and retain the Certificate of Completion after approval.18

What should you check before buying land in Union County?

Start with buildability, not the asking price. Only about 21.9% of Union County land is at a slope of 15% or less, and about 70.2% is wooded, so verify the actual homesite, access grade and clearing needs on the parcel.2122 Septic deserves equal attention because only about 11.4% of soils lack severe limitations for a conventional drain field.9

Confirm the zoning district, setbacks and permitted dwelling type with the county because Union County has zoning but the current district details were not confirmed.3 Check whether the site lies in a flood hazard area and ask the county who handles development approval there. A driveway on state highway right-of-way requires TDOT approval, while a county-road entrance should be discussed with the county before construction.20 For budgeting context, the effective property-tax rate is about 0.4%, and the median annual property-tax bill is about $720.1011

Watch-outs

  • Union County building permits must be purchased in person; the Assessor of Property does not offer them online.2
  • Do not start dirt work or prepare the building pad before obtaining the applicable septic approval.16
  • Union County's RV, tiny-home, setbacks, minimum-size and floodplain procedures remain unconfirmed; ask the county for parcel-specific written answers before closing.3
  • A state-highway driveway requires a TDOT entrance permit even when other county approvals are already in hand.20

Sources

  1. Union County Assessor of Property (2026 county census)
  2. Union County Assessor of Property (unioncountytn.gov)
  3. Union County Subdivision Regulations (2026 county census)
  4. TDEC - Subsurface Sewage Disposal Systems (SSDS) (2026 county census)
  5. TDEC Knoxville Environmental Field Office (tn.gov)
  6. Septic System Construction Permit (Tennessee statewide rule), quoted and re-checked
  7. Can I build my own home without a license? (2026 county census)
  8. Can I build my own home without a license? (Tennessee statewide rule), quoted and re-checked
  9. Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
  10. Effective property tax rate: Bolthole Index county data
  11. Median property tax bill: Bolthole Index county data
  12. Residential Permit FAQs (Tennessee statewide rule), quoted and re-checked
  13. Tennessee Attorney General Opinion No. 10-108 (Tennessee statewide rule), quoted and re-checked
  14. Exemption from County Zoning Regulation for Buildings on Land Used for Agriculture, Opinion No. 22-07 (Tennessee statewide rule), quoted and re-checked
  15. Subsurface Sewage Disposal System Frequently Asked Questions, quoted and re-checked
  16. Subsurface Sewage Disposal System Frequently Asked Questions, quoted and re-checked
  17. Subsurface Sewage Disposal System Frequently Asked Questions, quoted and re-checked
  18. Subsurface Sewage Disposal System Frequently Asked Questions, quoted and re-checked
  19. Online Application for Septic Related Services, quoted and re-checked
  20. Highway Entrance Permits (Tennessee statewide rule), quoted and re-checked
  21. Share of land at 15% slope or less: Bolthole Index county data
  22. Wooded share of land: Bolthole Index county data

Written September 27, 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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County locator

Union County in Tennessee

73
County map
Union County highlighted among the Tennessee counties · colored by Index score

How Union County scores

Seclusion51100% ev.
Self-Sufficiency63100% ev.
Admin Boringness46100% ev.
Durability76100% ev.
Property Autonomy71100% ev.
Carry Cost84100% ev.

Evidence strength: 100%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$299kTypical home
0.4%Property tax
$4,605Land / acre
53.2"Annual rain
1.9% of yrsSevere drought
3.6 / yr (+3.4)Mid-century 100°F days
13 daysMid-century dry spell
2.12" (+11.7%)Mid-century 1-day rain
1.71×Wildfire change factor
100%Forward climate coverage
$1,450Home insurance / yr
-1.5% / yrInsurance growth
0.93%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
23,132People within 30 min
2,023,136People within 2 hr
77,946Radius comparison (15 mi)
92.8People / sq mi
8.2%Federal land
21.9%Land at 15% slope or less
11.4%Septic soil without severe limits
14,491 acWorkable land screen
70.2%Wooded land
64.2 tonsBiomass / forest ac
57°FAvg temp

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Answers from the rulebook for Union County

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

Union County rules

  • County-wide zoningPresent

    Union County has an adopted zoning resolution and subdivision regulations and maintains a Planning & Zoning Coordinator.

    Union County Subdivision Regulations ↗Scouted from the county site, not yet independently re-checked

Tennessee rules that apply here

  • Building permitLimited

    State residential building permits for one- and two-family dwellings and townhouses in Tennessee jurisdictions where the State Fire Marshal's Office administers the residential building permit program.

    • The state permit is required only in some areas because other jurisdictions may enforce local residential building codes.
    • A county legislative body may remove unincorporated areas from the state program or a city legislative body may remove the city by a two-thirds vote.
    • The state permit does not replace grading or fill approval, floodplain compliance, septic or sewer permits, electrical permits, or zoning approval.
    • Local governments remain responsible for locally adopted codes and other requirements.
    “Why is the state residential building permit only required in some areas of the state?”
  • Owner-builder exemptionConditional

    A Tennessee property owner constructing a single residence for the owner's individual use.

    • The owner may have one permit every two years.
    • The residence must not be for sale, lease, or rent.
    • If the owner hires a contractor, the contractor is a prime and must be licensed and obtain the building permit for inspections.
    • Contracts may not be split into phases to circumvent the licensing law.
    • Anyone paid more than $25,000 by the owner is considered a prime and must be licensed.
    • The exemption is based on TCA 62-6-103 and Rule 0680-1-.22.

    owner permits: per 1 permit per two years · contractor payment threshold: > 25000 USD (Anyone paid in excess of this amount is considered a prime and must be licensed.)

    “one permit every two years to build their home as long as it is not for sale, lease, or rent (individual use).”
  • Certificate of occupancyLimited

    Certificates of occupancy for one- and two-family dwellings in Tennessee opt-out or non-code jurisdictions when the State Fire Marshal's Office inspects the dwelling during construction.

    • The owner or contractor may obtain a state building permit to request the inspection.
    • The Certificate of Occupancy is released only if the dwelling is determined to meet statewide building construction safety standards.
    • The source describes this process for opt-out or non-code jurisdictions and for new construction or additions to existing homes.
    “determined to meet the statewide building construction safety standards, the State Fire Marshal’s Office will release a Certificate of Occupancy”
  • Who permits septicState (with conditions)

    Subsurface sewage disposal permitting and final inspection applicable to Union County as a non-contract Tennessee county.

    • TDEC's Environmental Scientist conducts the site evaluation and final inspection.
    • The installer must contact the local Environmental Scientist before the system is covered.
    • If approved, TDEC issues a Certificate of Completion.
    “Counties Served Anderson, Blount, Campbell, Claiborne, Cocke, Grainger, Hamblen, Jefferson, Knox, Loudon, Monroe, Morgan, Roane, Scott, Sevier, Union”
  • Septic permitRequired

    Installation of a subsurface sewage disposal system on property in Tennessee, and repair of an existing faulty system.

    • A Septic System Construction Permit is required before installation or repair.
    • The application requires site and system information; soils maps may be required and large conventional or alternative systems require a licensed-engineer design.
    • The review generally takes 10 days and must be completed within 45 days.
    • New conventional permit fee is $400 up to 1,000 gallons per day, plus $100 for each additional 1,000 gallons per day.
    • New alternative permit fee is $500 up to 1,000 gallons per day, plus $150 for each additional 1,000 gallons per day.
    • Experimental SSDS permit fee is $500.
    • Repair permits have no permit fee; repair construction inspection fee is $100.
    • Contract counties Blount, Davidson, Hamilton, Jefferson, Knox, Madison, Sevier, Shelby, and Williamson may require an additional permit.

    new conventional SSDS permit fee: 400 USD up to 1000 gallons per day design flow ($100 for each additional 1000 gpd flow) · new alternative SSDS permit fee: 500 USD up to 1000 gallons per day design flow ($150 for each additional 1000 gpd flow) · experimental SSDS permit fee: 500 USD · repair permit fee: No permit fee

    “Any individual or property owner who desires to have a subsurface sewage disposal (septic) system installed on their property or requiring repair to an existing faulty system must get a Septic System Construction Permit.”
    One more reviewed finding on this topic
  • Septic inspectionRequired

    Final inspection of septic installations in Union County.

    • Final inspection occurs before the system is covered.
    • If approved, TDEC issues a Certificate of Completion.
    “schedule a final inspection before the system is covered”
  • Mandatory utility hookupSewer (with conditions)

    Residential, commercial, or industrial buildings on lots or parcels abutting a street or other public way containing a sanitary sewer, where the applicable Tennessee utility system has issued bonds payable for sewer services.

    • The cited Tennessee statute grants qualifying utility systems authority to require connection.
    • The building must exist on the abutting lot or parcel.
    • The owner, tenant, or occupant may be required to cease using other means for disposal of sewage, sewage waste, or other polluting matter.
    • This source describes authority to require sewer connection; it does not establish that every Tennessee property has sewer available.
    “Utility systems within the State of Tennessee that have issued bonds payable for sewer services are granted authority in TCA § 7-35-201 (1) to "require the owner tenant or occupant of each lot or parcel of land that abuts upon a street or other public way containing a sanitary sewer and upon which lot or parcel a building exists for residential, commercial or industrial use, to connect the building with the sanitary sewer and to cease to use any other means for the disposal of sewage, sewage waste or other polluting matter."”
    One more reviewed finding on this topic
    • Conditional — Electrical service for a proposed house or establishment using public sewer or septic service in Union County.
      “before the electrical inspector can process a request for electrical service”
  • Agricultural exemptionConditional

    Buildings or structures on land used for agricultural purposes and subject to county zoning regulation in Tennessee.

    • The building or structure must be located on lands devoted to agricultural uses.
    • The building or structure must be incidental to the agricultural enterprise.
    • The exemption does not apply to agricultural lands adjacent or in proximity to state or federal-aid highways, public airports, or public parks.
    • The exemption does not apply to land located within the one-hundred-year flood plain.
    • The Attorney General opinion states that the provision applies to counties only and has no application to municipalities.
    • There is no blanket exemption for cotton gins, grain elevators, slaughterhouses, processing plants, or milk bottling plants; those structures qualify only when the statutory conditions are met.
    “it must be located on lands “devoted to agricultural uses;” and (2) it must be “incidental to the agricultural enterprise.””
  • Driveway accessLimited

    Construction, modification, revision, or change in use of a driveway on Tennessee state highway right-of-way.

    • The requirement applies to state highway right-of-way and does not establish a permit requirement for every driveway on every road.
    • Property owners must obtain the permit from TDOT.
    • County or municipal land-use regulations may also apply.
    “Under state law, a permit is required before construction of a driveway on state highway right-of-way, including the modification, revision, or change in use”
  • Permit feesPublished (with conditions)

    Residential building permits administered by Tennessee's State Residential Building Code Enforcement Program for one- and two-family dwellings and townhouses where the state program applies.

    • The state program does not apply where a local government enforces local building codes under an exemption or where the city or county has opted out by a two-thirds vote.
    • For construction costs above the maximum listed in the table, an additional fee of $50.00 applies for each additional $50,000 or fraction thereof.
    • The construction cost cannot be less than $60.57 per heated square foot of construction.
    • An HVAC and Plumbing Inspection is required for all new construction.
    • A slab other than Monolith Pour Inspection is required when slab and footing are cast separately.

    permit fee for construction cost $0 to $5,000: 100 USD · permit fee for construction cost $5,001 to $100,000: 350 USD · additional fee for plumbing and HVAC inspection: 100 USD (Applicable as stated in the fee table.) · additional fee for slab other than monolith pour: 100 USD (Applicable when slab and footing are cast separately.)

    “$0 to $5,000 | $100 | $100 | $100 $5,001 to $100,000 | $350 | $100 | $100”
  • Permit processPublished (with conditions)

    Residential permit purchase and inspection process under Tennessee's State Residential Building Code Enforcement Program.

    • The state program applies to one- and two-family dwellings and townhouses only in areas without the stated local-code exemption or opt-out.
    • A first-time CORE user must register for an account.
    • A building permit must be purchased online or at a local Issue Agent.
    • Inspections cover the foundation before pouring, framing/rough-in construction, and final construction.
    • One free re-inspection is available; each additional re-inspection requires an additional fee.
    • A homeowner may build a home only if it will be the homeowner's residence, not sold or leased, and the homeowner has not received a homeowner building permit during the preceding 24 months.
    • Detached garages, sheds, barns, and other detached structures not used for living purposes do not require a state residential building permit.
    • A permit is not required for installation of a manufactured or modular home, but custom site work such as a deck, patio, or stoop requires a permit.

    effective date for permit requirement for additions over 30 square feet: 2011-10-01 (Applies to additions to existing homes.) · free re-inspections per project: 1 inspection (Available if a required inspection is not passed the first time.)

    “A building permit must be purchased online or at a local Issue Agent. The cost of the building permit is based on the estimated cost”
    One more reviewed finding on this topic
  • county zoning authorityGeneral

    County legislative bodies adopting zoning regulations for portions of Tennessee counties outside municipal corporations.

    • The authority is exercised under the conditions and procedures in Tennessee Code Annotated §§ 13-7-101 through 13-7-119.
    • The grant applies to portions of counties outside municipal corporations.
    • County zoning authority does not authorize county building permits or regulation of buildings or structures on agricultural land when the building or structure is incidental to the agricultural enterprise, except on agricultural lands adjacent or in proximity to state federal-aid highways, public airports or public parks.
    • The agricultural-land limitation applies to counties only and has no application to municipalities.
    “Under Tenn. Code Ann. § 13-7-101, et seq., the General Assembly has expressly delegated the authority to county legislative bodies to enact zoning regulations and create a board of zoning appeals.”

Still unanswered

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

  • Building code adopted — Building-code adoption in Union County.
  • Inspections — Building inspections in Union County.
  • Local zoning — Local zoning across Union County, including incorporated municipalities and unincorporated areas.
  • Zoning districts — Published zoning districts in Union County.
  • Minimum dwelling size — Minimum dwelling size in Union County.
13 more unanswered
  • Minimum lot size
  • Setbacks
  • Lot coverage
  • Building height
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Off-grid sanitation
  • Well permit
  • Building in a floodplain
  • 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 Union County, Tennessee

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

Union County scores 73/100 on the Bolthole Index, a strong county profile. Its strengths: manageable long-term carry cost and mixed durability signals.

Do you need a building permit in Union County, Tennessee?

Union County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Tennessee Department of Environment and Conservation (TDEC). Owner-builders may act as their own contractor to build their home. 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 Union County, Tennessee?

Land in Union County runs about $4,605 per acre, based on the latest county data.

What is the water situation in Union County?

Union County gets about 53.2" of rain a year, with severe drought in roughly 1.9% of years.

How remote is Union County?

A representative private-land location has about 23,132 people within a 30-minute drive and 2,023,136 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.

Off-grid gear

Going off-grid in Union County means bringing your own water and power. The kit we’d start with:

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How Union compares in Tennessee

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