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

The Unified Development Ordinance's watershed protection standards apply only within the six overlay districts established under UDO Sec. 11 -- M/LR-A, M/LR-B, F/J-A, F/J-B, E-A and E-A(2) -- which ring Lake Michie, the Little River Reservoir, and the Falls/Jordan and Eno River watersheds. Outside those overlays the UDO does not cap impervious surface citywide. Sec. 2 sets Low Density Option limits from 6% (M/LR-A and the M/LR-B and F/J-A Rural Tier) up to 24% (F/J-B, E-B and E-A/E-A(2)); High Density Option limits run from 24% (M/LR-B Rural Village) to 70% (F/J-B, E-B), with the High Density Option barred entirely in some overlays and Rural Tier areas.

S. Chapter 160D, and applies within the overlay boundary regardless of city/county line -- so a city-limits parcel in, say, the F/J-A overlay is bound by the same 6%-to-9% Low Density figures as a county parcel in the same overlay. Developers who need more impervious area than a parcel's Low Density Option allows can use an impervious surface credit transfer from a non-contiguous "donor parcel" in the same watershed, provided the donor land is permanently protected by a conservation easement in favor of the City or County.

Projects exceeding the Low Density Option maximum within a Critical Area (A) are also kicked out of administrative site plan review and into Major Site Plan review requiring Governing Body approval under UDO Sec. 3(B). Where the High Density Option is used, engineered stormwater controls sized to treat the first inch of rainfall are mandatory, and no building permit may issue until the City Public Works Director or County Engineer has approved the stormwater plans and an Operation and Maintenance Agreement is signed.