Bolthole Index

Mercer County, Kentucky

Building permits, zoning and septic rules in Mercer County, Kentucky

50Index Score / 100
#107 of 120 in Kentucky

Mercer County, Kentucky requires a building permit for virtually every structure placed on property in the county, including homes, manufactured homes, additions, garages and accessory structures larger than 200 square feet12. Residential applications begin with zoning review and then go to the Mercer County Building Inspector2. The published residential fee is $0.20 per square foot, with a $75 minimum3.

At a glance

Building permit
Required for virtually all structures in Mercer County and Harrodsburg12
Zoning
Yes, joint city-county zoning administered by the Greater Harrodsburg/Mercer County Planning & Zoning Commission45
Permit fee
$0.20 per square foot for residential work, with a $75 minimum3
Septic authority
Mercer County Health Department handles onsite evaluations and homeowner permits678
Owner-builder exemption
Not stated on the county's building inspection page; unconfirmed9
RV and tiny-home living
Unconfirmed for unincorporated land; ask Planning & Zoning before buying5
Floodplain permit
State and local permits are required for development in an identified floodplain10
Water well
No owner application or fee, but a Kentucky-certified driller must do the work11

Who to call

Building permits

Mercer County Building Inspector

Building and zoning permits, plan review and inspections for construction in Mercer County and Harrodsburg

(859) 734-3375

[email protected]

109 Short St., Harrodsburg, KY 40330

Zoning

Greater Harrodsburg/Mercer County Planning & Zoning Commission

Zoning administration, setbacks and land-use review for Mercer County and Harrodsburg, including unincorporated land

(859) 734-6066

[email protected]

109 Short St., Harrodsburg, KY 40330

Septic permits

Mercer County Health Department

Septic (onsite sewage disposal) site evaluations and permits for properties outside Harrodsburg's sewer system

(859) 734-2229

900 N. College St., Harrodsburg, KY 40330

Roads & driveways

Mercer County Road Department

Maintenance of county roads, right-of-ways and culverts; the office to ask about access onto a county road before applying for a state driveway permit

(859) 734-6341

[email protected]

894 Moberly Rd., Harrodsburg, KY 40330

Contact details are copied from each office’s official page and were checked against it on September 28, 2026.

Do you need a building permit in Mercer County, Kentucky?

Yes. Mercer County's zoning ordinance and building code require a building permit for virtually every structure placed on property in Mercer County or Harrodsburg, including homes, duplexes, manufactured homes, additions, decks, garages, in-ground pools and accessory structures larger than 200 square feet2. Kentucky's residential code does not require a permit for a single-family dwelling unless a local ordinance requires one, and Mercer County applies a local permit system121. The residential application lists a fee of $0.20 per square foot under roof for new construction and per square foot of affected area for renovations or occupancy changes, subject to a $75 minimum3. The county page lists concrete patios, driveways, fences under 6 feet, and agricultural structures on agriculturally zoned tracts larger than 10 acres as exemptions; the principal dwelling on such a tract is not exempt2.

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

The Mercer County Building Inspector is at 109 Short St., Harrodsburg, KY 40330 and can be reached at (859) 734-3375 or [email protected]2. Office hours are 8 a.m. to 12 p.m. and 1 p.m. to 4:30 p.m.; permits and plan reviews are normally handled in the morning, while field inspections occur in the afternoon2. The residential application asks for a PVA building information sheet, proof of ownership, construction plans or details, and a site plan13. The application also asks for proof of septic approval or a sewer tap and whether a driveway permit has been obtained13. Start with Planning & Zoning because staff verify use, setbacks and placement before sending the application to the Building Inspector for construction-plan and floodplain review2.

Does Mercer County have zoning?

Yes. Mercer County has a joint city-county zoning ordinance administered by the Greater Harrodsburg/Mercer County Planning & Zoning Commission4. The commission is at 109 Short St., Harrodsburg, KY 40330 and can be reached at (859) 734-60665. Planning staff verify the proposed use, setbacks and building placement before forwarding a permit application to the Building Inspector2. The available material does not establish countywide numeric setbacks, minimum lot size, minimum dwelling size, lot coverage or height limits, so ask the commission for the rules tied to the parcel's zoning district5. A manufactured home appears among the structures requiring a building permit, and the county page provides a separate manufactured-home site application2. Kentucky law also requires planning-commission approval before land in a planning-unit jurisdiction is subdivided, subject to the statutory agricultural-use exception1415.

How do septic permits work in Mercer County?

The Mercer County Health Department handles local onsite sewage work, and Kentucky's program begins with an onsite evaluation of soil and site conditions6. The environmental and administrative line is (859) 734-2229, and the office is at 900 N. College St., Harrodsburg, KY 403308. A permit from the local health department is required before an onsite system is constructed, installed or altered, and the permit follows the site evaluation16. A homeowner who installs the homeowner's own system must obtain a homeowner permit through the local health department7. A certified inspector must inspect the system before it is backfilled17. Only about 3.7% of Mercer County soils are rated without severe limitations for a conventional drain field, so make the site evaluation an early contingency rather than assuming a standard system will fit18.

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

We could not confirm a temporary or permanent RV, park-model or tiny-home occupancy rule for unincorporated Mercer County; ask the Greater Harrodsburg/Mercer County Planning & Zoning Commission about the parcel before buying5. Within Harrodsburg city limits, a travel trailer or recreational vehicle may not be used for permanent habitation, while temporary habitation requires a conditional-use permit from the Board of Adjustments & Appeals19. That Harrodsburg rule does not answer the question for unincorporated land. A statewide rule allowing temporary sleep in a lawfully parked vehicle on a public road, street or parking lot for less than 12 hours likewise does not authorize long-term RV living on private property20. For a tiny home, ask Planning & Zoning to confirm the allowed use, setbacks, dwelling-size standards and whether the design will be treated as a site-built, manufactured or recreational unit5.

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

  1. Ask the Greater Harrodsburg/Mercer County Planning & Zoning Commission to confirm the parcel's use, setbacks and placement2.
  1. Arrange the Mercer County Health Department's onsite evaluation if the project needs septic service6.
  1. Gather the PVA building information sheet, proof of ownership, construction plans or details, site plan, and proof of septic approval or a sewer tap13.
  1. Resolve driveway access; the application asks whether a driveway permit has been obtained, while the administering authority depends on the road13. A state-highway approach requires an application to the Department of Highways District Engineer21.
  1. Submit the residential application and fee to the Mercer County Building Inspector3.
  1. If development is in an identified floodplain, obtain both state and local floodplain permits10.
  1. If a well is needed, use a Kentucky-certified water-well driller; the owner does not file a separate well-permit application or pay a well-permit fee11.

What should you check before buying land in Mercer County?

Check septic feasibility before treating a building site as settled: only 3.7% of Mercer County soils are rated without severe limitations for a conventional drain field18. Check the parcel's zoning district and confirm allowed use, setbacks and placement with Planning & Zoning2. Check flood maps and permitting because development in an identified floodplain requires both state and local permits10. Confirm who controls the road before planning an entrance; the residential application asks about a driveway permit, and a connection to a state highway goes through the Department of Highways District Engineer1321. For water, a property owner does not need a separate well application or fee, but construction, modification and abandonment must be performed by a Kentucky-certified water-well driller11. For carrying costs, Mercer County's effective property-tax rate is about 0.8%, the median annual tax bill is about $1,553, and typical home insurance is about $1,410 per year222324.

Watch-outs

  • Mercer County's building inspection page does not state an owner-builder exemption from permit or licensing requirements; confirm directly with the Building Inspector before assuming one exists9.
  • No county or state source in this guide answers whether Mercer County allows full-time RV or tiny-home living on private land; call the Planning & Zoning Commission before relying on any general assumption5.
  • Harrodsburg's ban on permanent RV habitation applies within city limits and does not establish the rule for unincorporated Mercer County19.
  • The county page's farm-structure exemption applies to agricultural structures on agriculturally zoned tracts larger than 10 acres, not to the principal dwelling2.

Sources

  1. Building Inspection – Mercer County (2026 county census)
  2. Mercer County Building Inspector (mercercounty.ky.gov)
  3. Mercer County Joint Planning & Zoning Commission Fee Schedule, quoted and re-checked
  4. Planning & Zoning – Mercer County (2026 county census)
  5. Greater Harrodsburg/Mercer County Planning & Zoning Commission (mercercounty.ky.gov)
  6. Environmental Compliance FAQs, quoted and re-checked
  7. 902 KAR 10:110 Issuance of on-site sewage disposal system permits, quoted and re-checked
  8. Mercer County Health Department (mercercounty.ky.gov)
  9. (2026 county census)
  10. Find Your Flood Zone (Kentucky statewide rule), quoted and re-checked
  11. Water Well Information, quoted and re-checked
  12. 815 KAR 7:125, Kentucky Residential Code (Kentucky statewide rule), quoted and re-checked
  13. Building Inspection – Mercer County, quoted and re-checked
  14. KRS 100.277 — Commission approval required for subdivisions (Kentucky statewide rule), quoted and re-checked
  15. KRS 100.111 — Definitions for chapter (Kentucky statewide rule), quoted and re-checked
  16. 902 KAR 10:110. Issuance of on-site sewage disposal system permits (Kentucky statewide rule), quoted and re-checked
  17. 902 KAR 10:085. System Installation Inspection (Kentucky statewide rule), quoted and re-checked
  18. Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
  19. City of Harrodsburg Zoning Ordinance, quoted and re-checked
  20. KRS 511.110 — Unlawful camping (Kentucky statewide rule), quoted and re-checked
  21. 603 KAR 1:020 Driveway approaches, entrances; construction and maintenance (Kentucky statewide rule), quoted and re-checked
  22. Effective property tax rate: Bolthole Index county data
  23. Median property tax bill: Bolthole Index county data
  24. Typical home insurance premium: Bolthole Index county data

Written September 28, 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

Mercer County in Kentucky

50
County map
Mercer County highlighted among the Kentucky counties · colored by Index score

How Mercer County scores

Seclusion27100% ev.
Self-Sufficiency58100% ev.
Admin Boringness4190% ev.
Durability69100% ev.
Property Autonomy33100% ev.
Carry Cost81100% 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 →

$244kTypical home
0.8%Property tax
$5,326Land / acre
49.8"Annual rain
2.2% of yrsSevere drought
6.9 / yr (+6.5)Mid-century 100°F days
12.8 daysMid-century dry spell
2.05" (+6.3%)Mid-century 1-day rain
1.83×Wildfire change factor
100%Forward climate coverage
$1,410Home insurance / yr
0.3% / yrInsurance growth
0.58%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
97,912People within 30 min
3,536,604People within 2 hr
71,182Radius comparison (15 mi)
92.7People / sq mi
0.5%Federal land
69.8%Land at 15% slope or less
3.7%Septic soil without severe limits
5,733 acWorkable land screen
27.6%Wooded land
30.6 tonsBiomass / forest ac
55.8°FAvg temp

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Answers from the rulebook for Mercer County

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

Mercer County rules

  • Building permitRequired

    Structures placed or erected on property within Mercer County and Harrodsburg, subject to listed exemptions and state/local jurisdiction distinctions.

    • The county states that permits are required for virtually all structures.
    • Examples include homes, duplexes, multifamily buildings, manufactured homes, commercial structures, additions, decks, porches, garages, boat docks, gazebos, sun rooms, in-ground pools, renovations, occupancy-classification changes, and accessory structures larger than 200 square feet.
    • Exemptions listed by the county include concrete patios, driveways, fences under 6 feet in height, and certain agricultural structures in agriculturally zoned districts on more than 10 acres.
    • The agricultural exemption does not include the principal dwelling on a 10-acre-or-larger tract.
    • A zoning permit is required regardless of local or state permitting jurisdiction.
    “The zoning ordinances & building code require a building permit for virtually all structures that are placed or erected on a piece of property within Mercer County & Harrodsburg.”
  • InspectionsRequired

    Building construction inspections administered by the Mercer County building inspector and zoning enforcement officer.

    • Required building inspections listed are footer, foundation, framing, insulation, and final building inspection.
    • Plumbing inspections are performed on Tuesdays only and separate fees apply.
    • Final inspection follows final plumbing, electrical, and/or septic inspections.
    “Required Building Inspections 1. Footer Inspection 2. Foundation Inspection 3. Framing Inspection 4. Insulation Inspection 5. Final Building Inspection”
  • Certificate of occupancyRequired

    Projects requiring the county building inspection process and final occupancy approval.

    • Final plumbing, electrical, and/or septic inspections must be performed before the final inspection for the Certificate of Occupancy may be scheduled.
    • After completing all required inspections, the building inspector sends out the Certificate of Occupancy.
    “Once the final plumbing, electrical, and or septic inspections have been performed, the final inspection for the Certificate of Occupancy may be scheduled. After completing all the required inspections, the building inspector will send out the Certificate of Occupancy.”
  • County-wide zoningPresent (with conditions)

    Mercer County zoning and land-use controls administered through the Mercer County Joint Planning and Zoning Commission.

    • Burgin is excluded from the joint planning operation and has no zoning ordinances or maps according to the county zoning-maps page.
    • The county planning page lists MCZO 2026-01 as the Mercer County Zoning Ordinance 2026.
    “MCZO 2026-01.pdf (Mercer County Zoning Ordinance 2026)”
  • Local zoningVaries (with conditions)

    Aggregate of local zoning within Mercer County, including Mercer County zoning, Harrodsburg zoning, and the Burgin exception; this claim does not state that the county administers every municipal ordinance.

    • Harrodsburg and Mercer County zoning ordinances are listed on the county ordinances page.
    • Burgin does not participate in the joint planning operations and has no zoning ordinances or maps for properties within city limits.
    “Note: The City of Burgin, KY does not participate in the joint planning operations of the Commission and as a result, there are no zoning ordinances or maps for properties that reside physically within the city limits.”
  • Zoning districtsPublished (with conditions)

    Mercer County zoning districts and maps, subject to official zoning determinations by planning commission staff.

    • The county publishes 29 Mercer County maps plus a master county map.
    • The maps are general references and should not be relied upon to verify zoning.
    • Official zoning determinations should be made by contacting planning commission staff.
    • Burgin has no county joint-planning zoning ordinances or maps within city limits.
    “There are 29 maps plus a master county map for Mercer County. To determine which map is the right one to view, click on the map titled “Cover”. It is a master map that will show the various map grids.”
  • Who permits septicLocal (with conditions)

    On-site sewage disposal in Mercer County through the Mercer County Health Department as the local health department.

    • Kentucky's onsite sewage program is administered through local health departments.
    • The county building page identifies the Mercer County Health Department as the provider of septic evaluations for projects outside Harrodsburg city limits.
    “The Onsite Sewage Disposal Systems Program is administered through local health departments and begins with the use of onsite evaluations to determine if the site and soil conditions are suitable for onsite wastewater systems.”
  • Mandatory utility hookupConditional

    Projects outside Harrodsburg city limits in Mercer County.

    • The county requires a copy of the septic evaluation provided by the Mercer County Health Department.
    • The Mercer County Sanitation District provides wastewater service in areas outside the City of Harrodsburg Planning Area, but its webpage does not establish universal mandatory connection.
    “If the project is outside the city limits of Harrodsburg, you will also need: Copy of the Septic Evaluation provided by the Mercer County Health Department.”
  • Agricultural exemptionAvailable (with conditions)

    Agricultural structures in agriculturally zoned districts on land exceeding 10 acres.

    • The exemption applies to structures used for agricultural purposes in agriculturally zoned districts on more than 10 acres.
    • The exemption does not include the principal dwelling on a 10-acre-or-larger tract.

    minimum acreage: > 10 acres (Principal dwelling is not exempt)

    “Additionally structures used for agricultural purposes in agriculturally zoned districts on more than 10 acres of land. (This exemption does not include the principal dwelling on a 10 acre or larger tract of land)”
  • Subdividing landRegulated (with conditions)

    Subdivision or resubdivision of land within Mercer County, excluding Burgin, under the Harrodsburg-Mercer County Subdivision Regulations.

    • Burgin opted out of the Joint Planning Agreement.
    • All subdivision of land as defined by KRS 100.111(22) must receive planning commission approval.
    • A plat must be approved before land may be subdivided or the plat recorded.
    • Outside Harrodsburg and Burgin municipal limits, Mercer Fiscal Court approves proposed improvements.

    amendment date: 2024-03-12

    “All subdivision of land as defined in KRS 100.11 1 (22) as amended from time to time shall receive planning commission approval.”
  • Permit feesPublished (with conditions)

    Mercer County Joint Planning and Zoning Commission permit and planning fees.

    • The fee schedule is effective June 27, 2023.
    • The schedule was adopted by the joint commission and approved by Mercer County Fiscal Court on June 27, 2023.
    • Fees vary by permit and application type.

    residential building permit: 0.2 USD per square foot (Includes living space, decks, porches, garages, bonus rooms, storage buildings, and accessory structures; renovations and occupancy changes are included) · minimum permit fee: 75 USD (Any permit)

    “Building Permit Residential $ 0.20 per sqft. [...] Minimum Permit Fee (Any Permit) $ 75.00”
  • Permit processPublished (with conditions)

    Mercer County building and zoning permit process.

    • Applicants provide ownership/deed, construction plans, signed truss plans, PVA building information, subdivision plat or site plan if available, contractor insurance, and an affidavit of exemption.
    • Planning Commission staff verify setbacks, use, and placement.
    • The building inspector reviews construction plans and floodplain issues.
    • The permit must be posted where visible from the road.
    • Floodplain projects require special state Division of Water permits before the building permit is issued.
    “The permitting process begins in the office of the Planning Commission. Setbacks, use and placement is verified by commission staff. The permit is immediately forwarded to the building inspector who performs construction plan and flood plain review with the applicant or property owner.”

Kentucky rules that apply here

  • Building code adoptedAdopted (with conditions)

    Buildings constructed statewide in Kentucky, including residential and nonresidential construction subject to the Kentucky Building Code and Kentucky Residential Code.

    • The 2015 International Building Code is the mandatory state building code for buildings constructed in Kentucky, subject to Kentucky amendments in the 2018 Kentucky Building Code.
    • One-family dwellings, two-family dwellings, and townhouses are governed by 815 KAR 7:125 and the 2015 International Residential Code with Kentucky amendments in the 2018 Kentucky Residential Code.
    • Permits, inspections, and certificates of occupancy are not required for a single-family dwelling unless required by local ordinance.
    • Residential occupancies that are not single-family dwellings, two-family dwellings, or townhouses must comply with the 2015 International Building Code and the 2018 Kentucky Building Code.
    • Manufactured homes are governed by KRS 227.550 through 227.665.

    base building code: 2015 International Building Code (Kentucky amendments in the 2018 Kentucky Building Code supersede conflicting provisions) · residential code: 2015 International Residential Code; 2018 Kentucky Residential Code amendments (Applies to single-family dwellings, two-family dwellings, and townhouses under 815 KAR 7:125) · mandatory effective date: 2019-01-01

    “Building Code. The 2015 International Building shall be the mandatory state building code for all buildings constructed in Kentucky except that: (1) The Kentucky amendments in the 2018 Kentucky Building Code shall supersede any conflicting provision in the 2015 International Building Code; (2) One (1) family dwellings, two (2) family dwellings, and townhouses shall be governed by 815 KAR 7:125; and (3) Manufactured homes shall be governed by KRS 227.550 through 227.665.”
    2 more reviewed findings on this topic
    • Adopted — Single-family dwellings, two-family dwellings, and townhouses constructed in Kentucky, including Mercer County.
      “Except as provided in subsection (2) of this section, the 2015 International Residential Code for One (1) and Two (2) Family Dwellings (IRC) shall be the mandatory state residential building code for all single-family dwellings, two (2) family dwellings, and townhouses constructed in Kentucky, except that the Kentucky amendments in the 2018 Kentucky Residential Code shall supersede any conflicting provision in the 2015 IRC.”
    • Adopted (with conditions) — Kentucky buildings subject to the Kentucky Building Code; one- and two-family dwellings, townhouses, and manufactured homes are governed by separate provisions identified in the regulation.
      “The 2015 International Building shall be the mandatory state building code for all buildings constructed in Kentucky except that:”
  • Accessory dwellingsLimited

    Accessory dwelling units on lots containing a single-family home in a county containing a consolidated local government, when a new lease is initiated after June 27, 2025 and the lot is in a traditional single-family home zone.

    • The owner may not lease or allow the accessory dwelling unit to be occupied unless the owner primarily resides in the single-family home, multifamily housing unit, or accessory dwelling unit on the lot.
    • The restriction applies only in a county containing a consolidated local government.
    • A traditional single-family home zone is a zone that, as of January 1, 2025, did not include multifamily homes as a permitted use.
    • The restriction does not apply to a lot containing only one single-family home and no accessory dwelling unit.
    • The statutory effective date is June 27, 2025.

    new lease applicability date: > 2025-06-27 (The statute applies to new leases initiated after June 27, 2025.)

    “In a county containing a consolidated local government, for new leases initiated after June 27, 2025, a property owner shall not lease or allow to be occupied any single-family home, multifamily housing unit, or accessory dwelling unit located on a lot that contains a single-family home and that is located in a traditional single-family home zone, unless the owner primarily resides in the single-family home or multifamily housing unit or an accessory dwelling unit on the lot.”
  • Septic permitRequired

    On-site sewage disposal systems subject to Kentucky Cabinet administrative regulation, including systems in Mercer County.

    • Permit must be obtained from the local health department before construction, installation, or alteration.
    • The permit application includes DFS-307, a $50 on-site sewage disposal permit fee, and the fee established by the local board of health.
    • Cluster-system plan review is submitted to the Environmental Management Branch and carries a $600 fee payable to the Kentucky State Treasurer.
    • Permits are generally issued only to certified installers, subject to homeowner-permit exceptions.

    state on-site sewage disposal permit fee: 50 USD (Additional local board of health fee may apply) · cluster-system plan review fee: 600 USD (Payable by check or money order to the Kentucky State Treasurer)

    “KRS 211.350 provides that no person, firm, or corporation shall construct, install, alter or cause to be constructed, installed, or altered any on-site sewage disposal system subject to administrative regulation by the cabinet without having first obtained an on-site sewage disposal permit from the local health department.”
    One more reviewed finding on this topic
    • Required — Construction, installation, or alteration of an onsite sewage disposal system subject to Kentucky Cabinet regulation.
      “a permit to construct, install, or alter an on-site sewage disposal system shall be obtained prior to construction of any portion of that system.”
  • Septic inspectionRequired

    Every Kentucky onsite sewage disposal system that is installed, constructed, altered, or repaired.

    • Inspection must be by a certified inspector.
    • The installer must request that the installation inspection be scheduled and completed before the system is backfilled.
    • An installer affidavit may substitute for an initial inspection in the circumstances specified by the regulation, but the installation inspection requirement remains applicable.
    • A variance may not waive site evaluation or system inspection.
    “Every on-site sewage disposal system installed, constructed, altered, or repaired shall be inspected by a certified inspector.”
    One more reviewed finding on this topic
    • Required — On-site sewage disposal site evaluations and inspections in Mercer County under Kentucky's statewide program.
      “Local health department onsite septic system inspectors will perform site evaluations and inspections in Kentucky. A certified Kentucky onsite septic installer then must install the onsite sewage system based on the results of the site evaluation.”
  • Off-grid sanitationAllowed (with conditions)

    Use of an approved private onsite sewage disposal system for a building where a public sewer is unavailable.

    • The private sewage disposal system must be approved.
    • Construction, installation, alteration, or repair requires the applicable onsite sewage disposal permit and inspection requirements.
    • This finding addresses private onsite sewage disposal, not unregulated composting toilets, straight pipes, cesspools, or other sanitation methods not covered by the cited rule.
    “If a sewer is not available, the house drain from a building shall connect with an approved private sewage disposal system.”
  • Well permitLimited

    Construction, alteration, repair, or abandonment of water supply wells in Kentucky.

    • The person performing the work must first obtain a water well driller or water well driller assistant certificate from the Cabinet.
    • The certificate authorizes only the drilling methods stated on the certificate.
    • The cited sources establish driller certification rather than a separate owner-applied construction permit for ordinary water supply wells.

    minimum examination score: >= 70 percent (applicable examination)

    “A person shall not construct, alter, repair, or abandon a water well without first obtaining a water well driller or water well driller assistant certificate”
    One more reviewed finding on this topic
    • Not required — Construction or abandonment of a private water well by the property owner in Kentucky, including Mercer County.
      “In Kentucky, there are no permitting applications or fees for constructing or abandoning a water well required of the property owner.”
  • Driveway accessRequired

    New or additional private farm or single-family-dwelling driveway approaches requiring work in Kentucky Department of Highways rights-of-way, including Mercer County.

    • The owner or occupant must make formal written application to the District Engineer.
    • Approval by the District Engineer is required before the specified follow-on requirements apply.
    • The applicant must furnish required drainage pipe, tile, or other drainage structures at the applicant's expense.
    • The Department may participate up to $300 for the described drainage, grading, and surfacing work within right-of-way limits.
    • No indemnity bond or other security is required for a farm or single-family-dwelling driveway approach unless estimated construction cost within right-of-way limits exceeds $300.

    department participation limit: <= 300 USD (For described drainage, grading, and surfacing work within right-of-way limits) · security threshold: > 300 USD (Estimated construction cost within right-of-way limits)

    “The owner or occupant of property, who desires to construct new or additional private farm or single family dwelling driveway approaches, shall make formal application in writing”
    2 more reviewed findings on this topic
    • Required — New or additional private farm or single-family dwelling driveway approaches on Kentucky Department of Highways rights-of-way.
      “The owner or occupant of property, who desires to construct new or additional private farm or single family dwelling driveway approaches, shall make formal application in writing, to the District Engineer of the Department of Highways.”
    • Required — New, additional, relocated, or modified driveway entrance approaches serving commercial property or property used for a purpose other than farming or a single-family dwelling.
      “The owner or occupant of property, used for commercial or any purpose other than farming or single family dwelling, who desires to construct new or additional driveway entrance approaches, to relocate, or make other changes in existing driveway entrance approaches thereto, shall make application for a permit to the District Engineer of the Department of Highways upon standard forms furnished by the Transportation Cabinet.”
  • Building in a floodplainRequired

    Development in an identified Kentucky floodplain, including development in mapped A and AE zones.

    • Both a state and local floodplain permit are required for development in an identified floodplain.
    • State and local permits are required for development in A and AE zones.
    • The Kentucky Division of Water issues general or individual floodplain permits.
    • General permits cover eligible activities that do not change the Base Flood Elevation and have minimal flood-risk potential.
    • Developments that do not meet general-permit eligibility or could change the Base Flood Elevation require an individual permit.
    • The source directs applicants to consult the local floodplain coordinator for local requirements.

    general permit nonsubstantial improvement threshold: < 50 percent of structure valuation (including labor)

    “Any development in an identified floodplain in Kentucky requires a state and a local floodplain permit.”
    One more reviewed finding on this topic
    • Required — Development determined to be within a floodplain in Mercer County.
      “To protect structures from flood damage, Kentucky law (401 KAR 4:060) requires a state floodplain permit before starting any construction, demolition, or renovation within a floodplain.”
  • Campground & park staysTemporary only (with conditions)

    Sleeping temporarily in a recreational vehicle or other vehicle in a vehicle-based location covered by KRS 511.110.

    • The vehicle must be parked lawfully on a public road, street, or parking lot.
    • Sleeping and parking at the location must occur for less than twelve (12) hours.
    • This provision does not establish permission for long-term or permanent RV occupancy on private land.
    • KRS 511.110 separately prohibits camping in specified areas when the area has not been designated for sleeping or camping or the person lacks authorization.

    maximum sleeping and parking period: < 12 hours

    “Nothing in this section shall prevent a person from sleeping temporarily in his or her vehicle parked lawfully on a public road, street, or parking lot, where the sleeping and parking of the vehicle at the location occur for a period of less than twelve (12) hours.”
  • county zoning authorityGeneral

    Kentucky counties may adopt permanent land-use regulations, including zoning, through the applicable planning-unit process; this authority reaches county jurisdiction, including unincorporated areas, subject to the statutory planning prerequisites.

    • The planning commission and legislative bodies must have adopted the required comprehensive-plan elements before permanent zoning may be enacted.
    • The authority is exercised by legislative bodies and fiscal courts within the planning unit.
    • The quoted statute also authorizes zoning and land-use regulations for the listed public-health, safety, welfare, development, density, parking, fire and police protection, flood, transportation, public-facility, school, historic-district, agricultural-land, natural-resource, and other specially protected-area purposes.
    “When all required elements of the comprehensive plan have been adopted in accordance with the provisions of this chapter, then the legislative bodies and fiscal courts within the planning unit may enact permanent land use regulations, including zoning and other kinds of growth management regulations”
  • county building authorityGeneral

    Kentucky fiscal courts may adopt and enforce construction regulations and may require building permits for construction in the county, including residential construction in unincorporated areas.

    • The construction regulations must be adopted by county order or resolution.
    • The regulations operate pursuant to KRS 198B.060 and the Uniform State Building Code framework.
    • A county building inspector may administer the regulations.
    • No person may build, erect, construct, reconstruct, remodel, relocate, alter, or repair a building within the county without first obtaining a building permit from the building inspector when the county permit system applies.
    • Permit fees must be reasonable and may not exceed the cost of the service provided.
    • A person aggrieved by the building inspector's ruling, order, or decision may appeal under KRS 198B.070.

    permit fee ceiling: <= cost of the service provided

    “The fiscal court of any county shall have authority, by order or resolution, to adopt, and to enforce, regulations governing construction as defined by KRS 198B.010 pursuant to the provisions of KRS 198B.060.”

Inside cities and towns in Mercer County

Municipal rules found while researching the county. They apply inside that city or town, not to unincorporated land.

  • Living in an RVTemporary only (with conditions)

    Travel trailers and recreational vehicles within the City of Harrodsburg limits.

    • Travel trailers or recreational vehicles are not to be used for permanent habitation within the city limits.
    • Temporary habitation may be allowed only as a conditional use.
    • A Conditional Use Permit issued by the Board of Adjustments & Appeals is required.
    • The conditional use provision applies in any zoning district.
    “NOTE: A travel trailer or recreational vehicle is not considered as a mobile-home. As such, they are not designed for nor shall they be used for permanent habitation within the city limits. Travel Trailers may be allowed as a Conditional Use if the intent is for temporary habitation and shall require a Conditional Use Permit issued by the Board of Adjustments & Appeals in ANY zoning district.”
  • Mandatory utility hookupWater and sewer (with conditions)

    Building projects within the City of Harrodsburg.

    • Paid sewer and water tap fees are required before final inspection.
    • Projects outside Harrodsburg city limits instead require a septic evaluation from the Mercer County Health Department.
    “If the project is within the City of Harrodsburg, you will also need: Copy of paid sewer & water tap fees.(provided prior to Final Inspection)”

Still unanswered

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

  • Owner-builder exemption — A homeowner pulling a Mercer County residential building permit and acting as their own general building contractor.
  • Minimum dwelling size — Minimum dwelling sizes under the current Mercer County zoning ordinance and district schedule.
  • Minimum lot size — Minimum lot sizes under the current Mercer County zoning ordinance and district schedule.
  • Setbacks — Building and structure setbacks in Mercer County.
  • Lot coverage — Lot-coverage limits under the current Mercer County zoning ordinance.
5 more unanswered
  • Building height
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • 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 Mercer County, Kentucky

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

Mercer County scores 50/100 on the Bolthole Index, a solid county profile. Its strengths: manageable long-term carry cost and mixed durability signals. Watch-outs: about 97,912 people within a 30-minute drive and a weaker property-autonomy legal backdrop.

Do you need a building permit in Mercer County, Kentucky?

Mercer County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Mercer County Health Department. 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 Mercer County, Kentucky?

Land in Mercer County runs about $5,326 per acre, based on the latest county data.

What is the water situation in Mercer County?

Mercer County gets about 49.8" of rain a year, with severe drought in roughly 2.2% of years.

How remote is Mercer County?

A representative private-land location has about 97,912 people within a 30-minute drive and 3,536,604 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 Mercer County means bringing your own water and power. The kit we’d start with:

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How Mercer compares in Kentucky

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