Rutherford County, TN Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- AR/RL residential coverage cap
- 20% (50% other uses)
- RM coverage cap
- 40% flat
- Accessory building size, ≤1 acre
- 2,000 sq. ft. combined
- Accessory building size, >1 acre
- 5% of lot area
- Exempt structures
- Agricultural buildings
- Relief path
- BZA variance, § 1407
Summary
Unincorporated Rutherford County caps how much of a lot a building can cover by district: 20% for residential uses in the AR and RL districts and 40% flat in the RM district, per Table 1 of Zoning Ordinance Section 404. Detached accessory buildings count toward that same cap under Section 1101 D.
3. The total area of structures including all detached accessory structures shall not exceed the maximum lot coverage allowed by the zoning district; 4. For all permitted residential uses, detached accessory buildings incidental to a permitted use shall be limited in size based on the table below. Square footage measurements of detached accessory structures shall include the entire structure, including any expandable areas accessed by a formal staircase (e.g. bonus rooms on a second floor), finished or unfinished: Size of Parcel Total Combined Square Footage for all Accessory Structures 1 acre or less 2,000 sq. ft. More than 1 acre 5% of Lot Area ... Buildings used for agricultural purposes are exempt from these totals.
Full Breakdown
Section 404's Table 1, Residential Districts Bulk Regulations, sets maximum lot coverage alongside minimum lot size, width and setbacks for each residential district. The Agricultural Residential (AR) and Low Density Residential (RL) districts cap coverage at 20% for residential uses and 50% for other uses, both under a 35-foot height limit. The Medium Density Residential (RM) district allows 40% coverage, also at 35 feet of height. These figures apply to zone lots and buildings, including enlargements, extensions and conversions, and existing structures that already exceed them become nonconforming under Chapter 13 rather than being grandfathered outright.
3 states the total area of structures, including all detached accessory structures, cannot exceed the maximum lot coverage allowed by the zoning district. 4 then layers on a separate square-footage cap for detached accessory buildings on residential lots: 2,000 square feet combined on a parcel of one acre or less, or 5% of lot area on parcels larger than one acre, counting the whole structure including any staircase-accessed bonus space. Buildings used exclusively for agricultural purposes are exempt from both the accessory-structure size table and the Section 404 bulk table entirely.
Storm shelters, swimming pools, tennis courts and similar recreational features are not counted as buildings for the accessory square-footage calculation, though they still count as impervious coverage for stormwater purposes elsewhere in the code. A property owner who cannot meet the district's lot coverage limit can apply to the Board of Zoning Appeals for a variance under Section 1407, but the Board must find genuine physical hardship tied to the lot itself; financial hardship alone does not qualify, and the variance must be the minimum needed for reasonable use of the land.
Violations & Fines
Building or expanding a structure beyond the maximum lot coverage set in Table 1 or beyond the accessory-structure size limits in Section 1101 D.4 without a variance is a zoning violation. Complaints go to the Director of Building Codes under Section 1410 A, each day of the violation is a separate offense under Section 1410 B, and the county or an especially damaged neighbor can seek an injunction to require removal or correction under Section 1410 C.
Frequently Asked Questions
What is the maximum lot coverage in unincorporated Rutherford County?
Do sheds and detached garages count toward the lot coverage limit?
Are there exceptions to the accessory building size table?
What if my lot cannot meet the coverage limit?
Sources & Official References
Other rules in Rutherford County
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