Sumner County, TN Building Setbacks & Zoning: Lot Coverage Limits (2026)

Table 1 of Section 404, the Residential Districts Bulk Regulations table, sets a distinct Maximum Lot Coverage percentage for each of the county's five residential zoning districts. Agricultural Reserve (AR), Rural Preservation (RP), and Rural Residential (RR) districts, the county's largest-lot categories, cap residential lot coverage at 20%, while Suburban Residential (SR), the smallest-lot residential district, allows 25%. Non-residential uses permitted within any of those four districts get a more generous 50% coverage cap. Mobile Home Community (MHC) districts run on a flat 40% maximum, with no separate residential/non-residential split.

The Resolution defines Lot Coverage, at the definitions appendix, as the portion of a zone lot covered by buildings and structures when viewed directly from above, so the percentage counts roofprint, not just the footprint of a single building. Section 1101, Subsection D(4) reinforces the cap for accessory structures specifically: detached garages, sheds, and other accessory buildings cannot, in combination with the principal structure and any other buildings on the lot, exceed the maximum lot coverage set for the zoning district in Table 1. Commercial, office/institutional, and industrial districts carry their own coverage percentages in Tables 2 through 4 of Sections 504, 604, and 704, generally also set at 50%, so a homeowner converting part of a residential lot to a permitted non-residential use should check both the district's residential and non-residential figures before adding square footage.