Sumner County, TN Accessory Structures: Tiny Homes (2026)
Tiny home rules in Sumner County, TN, covering tiny houses on wheels (THOWs), park model RVs, and tiny home on foundation builds, determine where they are legal and how they get permitted.
Key Facts
- On Foundation
- Dwelling under 2021 code
- As Second Unit
- Meets Sec. 1101(R) ADU
- Min Size
- 300 square feet detached
- On Wheels
- RV / mobile home rules
- Mobile Home ADU
- Special exception required
Summary
A tiny home's status in Sumner County depends on its foundation. On a permanent foundation it is a dwelling under the 2021 residential code; as a second unit it must meet the ADU rules in Section 1101(R). On wheels, it needs a special exception.
An ADU must however, provide the minimum area requirement of 300 square feet.
iv. 20,000 square feet of land area is required if connected to public sewer. 40,000 square feet of land area is required if utilizing a septic system.
c. Agricultural employee housing shall only be required to comply with all standards of this section deemed applicable by the County.
4. ADUs Requiring a Special Exception
a. Special Exception Required.
Applications for an ADU requiring a Special Exception from the Board of Zoning Appeals are listed as follows:
i. The Design and Occupancy Standards and Particular
Standards for By-Right ADUs contained in this Chapter
cannot be met.
ii. Applications for an ADU involving a mobile home.
b. The Board of Zoning Appeals may impose additional standards or use conditions beyond those enumerated above related to screening and buffering if deemed necessary by the Board.
5. Existing ADUs
Legally created accessory dwelling units established prior to the enactment of these regulations may continue to exist and will be regulated by the conditions under which they were approved.
6. Abandonment of an ADU
A property owner may choose to abandon an ADU by meeting the following criteria:
Full Breakdown
Sumner County treats a foundation-built tiny house as a dwelling that must meet the 2021 ICC residential code adopted in 2023, with a building permit before work begins and TDEC verification of septic capacity. Whether it can sit as a second home on the lot is governed by the accessory dwelling unit rules in Zoning Resolution Section 1101(R): a detached ADU must be at least 300 square feet, cannot exceed the main house, needs 20,000 square feet of land on sewer or 40,000 on septic, and must be owner-occupied and not rented. A tiny home on wheels reads as an RV or mobile home, and an ADU involving a mobile home requires a Board of Zoning Appeals special exception.
Violations & Fines
Placing a foundation-built tiny home without a permit is unlawful construction. Living in an RV-style tiny home as a dwelling, or an ADU involving a mobile home without a special exception, is a zoning violation.
Frequently Asked Questions
Can I put a tiny home in my backyard?
Can I live in a tiny home on wheels?
Sources & Official References
Other rules in Sumner County
Compare Sumner County to another location·View the Tennessee accessory structures overview
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