Sullivan County, TN Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- Principal structure cap
- None since Aug. 2005 amendment
- Accessory structure cap
- 10% of lot area, all districts
- Parcel-wide accessory cap
- 5% of total parcel acreage (2024)
- Exception
- OSRD planned developments, § 3-104.3
- Applies in
- Unincorporated Sullivan County only
Summary
Sullivan County dropped its lot-coverage cap on houses in 2005, but accessory structures still face two limits: Table 3-103B caps any single accessory building at 10% of the lot in every agricultural and residential district, and a 2024 amendment separately caps all accessory structures combined at 5% of the total parcel acreage.
4. Maximum Permitted Lot Coverage - The maximum zone lot coverage by all buildings, principal and accessory in these residential districts, shall not, except OSRD planned developments as provided in Subsection 3-104.3, exceed the percentage of the total area of the zone lot indicated in TABLE 3-103B. (Amended August 15, 2005 - no lot coverage required for principal dwelling structures). ... IV. Maximum Lot Coverage by the Accessory Structure*(%) 10% 10% 10% 10% 10% 10% 10% ... iv. The total maximum area coverage of all residential accessory structures cannot exceed five (5%) percent of the total parcel (lot/tract) acreage (Amended 03/14/2024).
Full Breakdown
3(4), 'Maximum Permitted Lot Coverage,' ties the county's coverage limit to Table 3-103B and notes it was 'Amended August 15, 2005 - no lot coverage required for principal dwelling structures,' which is why the table's row for principal-structure coverage now reads 'N/A' across every district. The operative number sits in Table 3-103B, row IV, 'Maximum Lot Coverage by the Accessory Structure,' set at a flat 10% of lot area in the A-5/A-2, A-1, AR/A-RV/RRC, R-1, R-2/R-2A, R-3A/R-3B and R-3 districts alike. 6(2)(c)(iv), amended March 14, 2024, caps 'the total maximum area coverage of all residential accessory structures' at five percent of the total parcel acreage, closing the gap where a landowner could otherwise build several 10%-sized outbuildings on one large tract.
3, which allows greater principal-building coverage and reduced side and rear setbacks as long as overall project density stays within what conventional zoning would allow.
Violations & Fines
Exceeding either the 10% single-structure cap or the 5% parcel-wide accessory cap is a zoning violation. Section 12-107.2 makes the violation a misdemeanor with a civil penalty up to $500 for each day it continues, and Section 12-107.3 authorizes the Building Commissioner, or a damaged adjoining owner, to seek an injunction or other court action to correct or remove the noncompliant structure.
Frequently Asked Questions
Is there a limit on how much of my lot my house can cover in Sullivan County?
How much of my lot can a shed or detached garage cover?
If I already have a shed at 10% coverage, can I add a second one?
Sources & Official References
Other rules in Sullivan County
Compare Sullivan County to another location·View the Tennessee building setbacks & zoning overview
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