Rockingham County, VA Accessory Structures: ADU Rules (2026)

The Rockingham County Zoning Ordinance regulates a 'Dwelling, accessory' as a supplemental standard at Sec. 17-607, distinct from an 'additional dwelling,' an 'in-house security service dwelling' or a 'temporary family health care structure' addressed elsewhere in the same section. Two baseline limits apply on every parcel countywide: the enclosed area used for the accessory dwelling cannot exceed fifteen hundred square feet, and a parcel is allowed only one accessory dwelling at a time, no matter the lot's size or the number of other structures on it.

That combination lets a property owner add a garage apartment, in-law suite or similar secondary living space without turning the parcel into a small multifamily site. A third requirement applies specifically in the county's more residential and mixed-use districts, R-1, R-2, PSF, MXU, R-4 and R-5: every accessory dwelling in those districts must have direct vehicular access to a public or private street, rather than relying on a shared driveway or access easement running through the principal dwelling's lot alone. That access requirement doesn't apply to accessory dwellings in the county's agricultural A-1 and A-2 districts or its rural RV district, where the 1,500-square-foot cap and one-per-parcel limit are the only supplemental standards in play.

An applicant still has to secure whatever building permits and zoning approvals the underlying district otherwise requires; Sec. 17-607 layers these size, count and access conditions on top of that baseline review rather than replacing it.