Building permits, zoning and land rules in Union Township, Ohio

At a glance

Building permit

Required for new homes and other covered residential work¹

Zoning

Administered by Warren County in unincorporated Union Township²

Septic

Installation and operating permits required through the county health district⁵

Private well

Health-district permit required before installation or alteration⁴

RV living

Not allowed on private property outside a mobile-home or RV park⁶

Manufactured home

Permanently sited homes allowed where single-family homes are permitted, subject to uniform zoning standards⁷

Agricultural building

Conditional zoning and building exceptions may apply after zoning-office verification⁸

Who to call

Contact details are copied from each office’s official page and were checked against it on October 9, 2026.

Do you need a building permit in Union Township, Ohio?

Yes. Warren County requires building permits for new one-, two- and three-family structures in Union Township, as well as additions, remodels and detached structures.¹ The Warren County Building & Zoning Department is the building office; its residential instructions direct applicants to upload plan files through the citizen portal and keep approved construction plans at the site for inspections.⁹

Building approval and zoning approval answer different questions. Warren County also administers zoning for unincorporated Union Township, so confirm the parcel's zoning district and obtain the necessary zoning approval before treating a building permit as the only land-use approval.² The building office is at 406 Justice Drive, Lebanon, OH 45036 and can be reached at 513-695-1290.⁹

Who handles zoning and building permits in Union Township?

The Warren County Building & Zoning Department handles residential building applications, plan review and inspections for Union Township.¹ Applications and plan files can be submitted through the county's online citizen portal.⁹

For land-use questions, the Warren County Zoning Department expressly lists Union Township among the townships it serves.² Contact Rural Zoning at 513-695-1294 to identify the parcel's mapped district, confirm its permitted use and learn which district standards control the proposed site plan.¹⁰ Septic and private-water approvals do not come from the building or zoning desk: the Warren County Health District handles those systems throughout Warren County.³⁴

Does Union Township have zoning?

Yes. Warren County administers zoning in unincorporated Union Township, and the official zoning map controls a parcel's current district.²¹¹ District identification matters because lot size, setbacks, building height and lot coverage can vary by district.¹²¹³

The A1 Agricultural Zoning District includes a provision describing at least 10 acres of vacant land, while non-agricultural development in A1 is limited to 5% maximum lot coverage.¹⁴¹⁵ Those A1 figures should not be applied to a parcel in another district. Permanently sited manufactured homes cannot be prohibited where single-family homes are permitted, but they must meet the zoning requirements uniformly applied to single-family residences in that district.⁷ Ask Rural Zoning to confirm the map and standards before relying on acreage or a building layout.¹⁰

How do septic and well permits work in Union Township?

The Warren County Health District issues permits and conducts inspections for new, replacement and altered onsite sewage systems in Union Township.³ Before installation, obtain a soil evaluation and system design, submit the site-review application, and secure both the sewage-system installation permit and operating permit.⁵ The registered installer must schedule inspection before backfilling; after final approval, the health district continues periodic inspections through its operation and maintenance program.¹⁶

Site feasibility deserves early attention because only 0.7% of Warren County soils are rated without severe limitations for a conventional septic drain field.¹⁷ A new or altered private well or other private water system also needs a health-district permit before work begins, followed by inspection and an acceptable water sample.¹⁸ Environmental Health is at 416 S. East St., Lebanon, OH 45036 and can be reached at 513-695-1220.¹⁹

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

Union Township's applicable Warren County zoning code does not allow occupancy of a travel trailer on private property unless it is in a mobile-home park or, for limited periods, in a recreational-vehicle park.⁶ That restriction means an RV should not be treated as temporary housing on a building lot without written confirmation from Rural Zoning.⁶

We could not confirm a separate Union Township rule for tiny homes or a minimum dwelling size. Ask Rural Zoning at 513-695-1294 how a proposed tiny home is classified and which mapped-district standards apply.¹⁰ A permanently sited manufactured home is a different category: it is allowed where a single-family home is permitted if it complies with the zoning requirements uniformly imposed on single-family residences in that district.⁷ Septic and private-water permits still come from the Warren County Health District.⁵⁴

How do you build a home in Union Township?

1. Ask Warren County Rural Zoning to confirm that the parcel is in unincorporated Union Township, identify its mapped district and review the proposed use, lot dimensions and setbacks.²¹¹

1. Obtain the zoning approval required for the project before finalizing the site plan.²

1. If the site needs onsite sewage, complete the soil evaluation and system design, then obtain site review, an installation permit and an operating permit from the health district.⁵

1. Obtain the health-district permit before installing or altering a private water system.⁴

1. Submit the residential building application and plan files through the Warren County citizen portal, then keep the approved plans at the job site for inspections.⁹

1. Have the registered sewage installer arrange inspection before the system is backfilled.¹⁶

What should you check before buying land in Union Township?

Start with the zoning map. Warren County zoning applies in unincorporated Union Township, but the parcel's district determines the operative dimensional and use standards.²¹¹ Do not assume that an A1 acreage or lot-coverage rule applies outside A1.¹⁴¹⁵

Investigate sewage feasibility before treating a parcel as buildable. Only 0.7% of Warren County soils rate without severe limits for a conventional septic drain field, and the health district requires a soil evaluation, system design and site review before installation approval.¹⁷⁵ Confirm private-water permitting if public water is unavailable.⁴

We could not confirm the parcel-specific floodplain process or which agency controls a driveway onto each road type. Ask Rural Zoning which floodplain office and road authority apply before fixing the house or driveway location.¹⁰

Watch-outs

• Warren County zoning serves unincorporated Union Township, but the official zoning map determines the parcel's district and applicable standards.²¹¹
• Do not plan to occupy a travel trailer on private land; the applicable zoning rule limits occupancy to mobile-home parks or limited periods in recreational-vehicle parks.⁶
• Do not backfill a new or altered septic system before the registered installer schedules the health-district inspection.¹⁶
• Agricultural structures receive a building exception only after the zoning inspector verifies agricultural use; electrical work still requires an electrical permit.⁸

Sources

1. Warren County Building & Zoning Department (2026 county census)
2. Warren County Zoning Department (Union Township), quoted and re-checked
3. Sewage Treatment Systems (Union Township), quoted and re-checked
4. Private Water Systems (Union Township), quoted and re-checked
5. Sewage Treatment Systems (Union Township), quoted and re-checked
6. Zoning Frequently Asked Questions (Union Township), quoted and re-checked
7. Warren County Rural Zoning Code, Article I, Chapter 1 (Union Township), quoted and re-checked
8. Frequently Asked Questions - Permits (Union Township), quoted and re-checked
9. Warren County Building & Zoning Department (warrencountyohio.gov)
10. Warren County Zoning Department (Rural Zoning) (warrencountyohio.gov)
11. Warren County Rural Zoning Code, Article I, Chapter 1 (Union Township), quoted and re-checked
12. Warren County Rural Zoning Code, purpose and applicability, quoted and re-checked
13. Warren County Rural Zoning Code, purpose and applicability, quoted and re-checked
14. Warren County Rural Zoning Code, Article II, Chapter 4 (Union Township), quoted and re-checked
15. Warren County Rural Zoning Code, Article II, Chapter 4: Other Use Specific Zones Regulations, quoted and re-checked
16. Sewage Treatment Systems (Union Township), quoted and re-checked
17. 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
18. Private Water Systems (Union Township), quoted and re-checked
19. Warren County Health District - Environmental Health (warrencohealthoh.gov)

Written October 9, 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.