Franklin County, NC Building Setbacks & Zoning: Lot Coverage Limits (2026)

Franklin County's Unified Development Code limits how much of a single-family lot's building envelope, the area inside the required setback lines defined in UDC section 10.1.3 (definition 43, Building Setback Line), a home's footprint may occupy. Under section 5.3.4.A.2.b, at the time of construction the footprint of the primary structure, treated as impervious surface, may not exceed 70% of the building envelope; the remaining 30% must stay open within the setback area. This coverage cap is separate from the front-yard impervious limit in section 5.3.4.A.2.c, which caps driveway, parking and walkway coverage in the required front yard at 40% for single-family and duplex lots.

The Building Envelope is illustrated in Figure 5-1 and cross-referenced to Figure 10-3, which shows how the Building Setback Line delineates the buildable area on all four sides of the lot. The rule applies once at the time the primary structure is built, meaning it governs plan review and building permit issuance by the Franklin County Building Inspector and the Planning and Inspections Department rather than an ongoing measurement. A site plan showing a footprint exceeding 70% coverage of the building envelope is rejected at permit review; if a structure is built in violation, the Administrator investigates under UDC section 3.3.1, issues a notice and correction order under sections 3.3.2 and 3.3.3 that is appealable to the Board of Adjustment under section 3.3.4, and can pursue a civil penalty of up to $500.00 under section 3.4.2.C or prosecution as a Class 3 misdemeanor with a $500.00 maximum fine under section 3.4.2.D and G.S. section 14-4.