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

Section 26-280 of the Zoning Ordinance sets standards applicable to all accessory housing units in Hanover County outside the Town of Ashland. Only one accessory housing unit is allowed per zoning lot, and any external access to it must be located in a side or rear yard rather than facing the street. The unit cannot exceed twenty-five percent of the living area of the main building, where living area is defined as finished floor area including finished basements but excluding attics and attached garage space; this ties the accessory unit's maximum size directly to the size of the primary house.

Two off-street parking spaces must be provided for the accessory housing unit, on top of the parking required for the principal residence, and no more than two bedrooms may be built into it. The site also must comply with every other requirement of the Hanover County Code, including the Zoning Ordinance and Subdivision Ordinance, before the county issues a permit, special exception, or extension of a permit or special exception under this section. Separate subsections of 26-280 govern family-member occupancy, which requires a special exception limited to three-year terms subject to renewal, and medical-hardship occupancy, which requires a caregiver's verified medical statement and runs up to two years with extensions.

The Zoning Administrator and the Board of Supervisors, through the special exception process, administer these standards, most recently amended by Ord. No. 25-10, Section 6, effective August 27, 2025.