Building permits, zoning and septic rules in Union, Kentucky

At a glance

Building permits

City adopts Kentucky building standards; confirm application requirements with Union City Hall¹²

Zoning

Union adopts Boone County zoning regulations and map by reference³

Septic permits

Northern Kentucky Health Department; site evaluation before installation approval⁴⁵

RV living and tiny homes

We could not confirm city occupancy rules; ask Union City Hall for the applicable zoning provisions³²

Lot size and setbacks

Ask for the adopted zoning map and district standards at city offices⁶

Private wells

No property-owner well application or fee; Kentucky Certified Water Well Driller required⁷

Who to call

Contact details are copied from each office’s official page and were checked against it on October 12, 2026.

Do you need a building permit in Union, KY?

Union adopts the Kentucky Building Code, Kentucky Plumbing Code and Kentucky Standards of Safety, including amendments, and identifies the Chief Building Official as the local building-code enforcement agent.¹ Kentucky’s statewide residential rule does not require a single-family building permit unless the local government requires one by ordinance.⁸ We could not confirm Union’s building permit application procedure, inspection schedule or certificate-of-occupancy requirements; ask Union City Hall to identify the responsible building official and confirm those requirements for your proposed project.²

Who handles building and zoning questions in Union?

Start with Union City Hall at 859-384-1511 for help identifying the city’s building-code enforcement contact and obtaining the adopted zoning provisions.² Union’s zoning regulations are available for public inspection during normal hours at city offices.⁶ Ask for the zoning map designation of the actual parcel, the application route for zoning approval and building permits, and the current fee schedule.⁶² For land outside Union city limits, use the Boone County guide: the county’s zoning rules apply to unincorporated Boone County.⁹

Does Union have zoning, and can you live in an RV or tiny home?

Union has zoning: the city adopts the most recent Boone County Zoning Regulations and Zoning Map, together with amendments, by reference.³ The adopted zoning text and map are the starting point for a parcel-specific discussion of a home, accessory dwelling or temporary living arrangement.⁶ We could not confirm Union’s RV occupancy, temporary camping, tiny-home or manufactured-home placement rules, or the city’s minimum dwelling size, lot size and setbacks; ask Union City Hall for the provisions that apply to your parcel and proposed use before buying equipment or committing to a site plan.²⁶

How do septic permits work inside Union?

Septic systems inside Union fall within the Northern Kentucky Health Department’s Boone County service area; the department handles site evaluations, installation permits and inspections.⁴⁵ A new system begins with a site evaluation application and a $300 evaluation fee; a certified installer may apply for the installation permit if the site is suitable or provisionally suitable.⁵ The installer must request inspection before covering any work.¹⁰ Existing systems may also need inspection for a building addition or remodeling permit.¹¹ Boone County’s soil screening rates only 0.2% of soils “not limited” for a conventional drain field; this county-level rating supports getting a site evaluation, not concluding that a Union lot cannot support septic.¹²

Building a home in Union: what are the steps, in order?

1. Ask Union City Hall for the parcel’s adopted zoning district and the provisions for your proposed home and accessory uses.⁶²
2. Ask the city to identify the responsible building official and confirm building permit applications, inspections and occupancy approval before scheduling construction.¹²
3. Establish sewer availability; Kentucky requires an approved private sewage disposal system when sewer is unavailable.¹³
4. For septic, complete the health department’s site evaluation and installation approval steps before construction begins.⁵
5. Arrange the septic installation inspection before work is covered.¹⁰

What should you check before buying land in Union?

For a private well in Union, Kentucky does not require a property-owner permitting application or fee, but construction, modification and abandonment must be performed by a Kentucky Certified Water Well Driller.⁷ Development in an identified Kentucky floodplain requires state and local floodplain permits; ask Union City Hall to identify the local floodplain coordinator for the parcel.¹⁴² A new or additional single-family driveway approach on a Kentucky Department of Highways right-of-way requires written application to the District Engineer.¹⁵ We could not confirm Union’s driveway application requirements for city streets or parcel-specific public water and sewer availability; ask Union City Hall for the correct street and utility contacts.²

Watch-outs

• Union’s adoption of building standards does not by itself establish the city’s single-family building permit procedure; confirm the local requirement with Union City Hall.¹⁸²
• We could not confirm Union’s RV or tiny-home occupancy rules; ask Union City Hall for a parcel-specific zoning answer before planning to live on the site while building.²³
• Septic approval should precede construction, and the installer must request inspection before covering the system.⁵¹⁰

Sources

1. § 150.15 Adoption of Kentucky Building Code and standards of safety; enforcement agents (Union), quoted and re-checked
2. Union City Hall (cityofunionky.org)
3. § 154.01 Adoption by reference (Union), quoted and re-checked
4. Septic System Inspections, quoted and re-checked
5. Septic System Inspections, quoted and re-checked
6. § 154.01 Adoption by reference (Union), quoted and re-checked
7. Water Well Information for Home Owners (Kentucky statewide rule), quoted and re-checked
8. 815 KAR 7:125, Kentucky Residential Code (Kentucky statewide rule), quoted and re-checked
9. How Do I Start or Expand a Business?, quoted and re-checked
10. Septic System Inspections, quoted and re-checked
11. Septic Systems - Northern Kentucky Health Department, quoted and re-checked
12. 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
13. 815 KAR 20:130. House sewers and storm water piping; methods of installation (Kentucky statewide rule), quoted and re-checked
14. Find Your Flood Zone (Kentucky statewide rule), quoted and re-checked
15. 603 KAR 1:020 Driveway approaches, entrances; construction and maintenance (Kentucky statewide rule), quoted and re-checked

Written October 12, 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.