Montgomery County, VA Building Setbacks & Zoning: Lot Coverage Limits (2026)

Section 10-21 sets a two-part coverage cap for property zoned A-1 Agricultural: no more than 20 percent of any lot may be covered by buildings, and no more than 30 percent of any lot may be covered by impervious surfaces, a broader category that reaches driveways, parking areas and other paved or hard surfaces in addition to structures. 0-acre minimum lot area, a 120-foot minimum lot width at the front setback line, and a maximum 5:1 length-to-width ratio for lots under 20 acres. Because the impervious limit is wider than the building-only limit, a landowner can pave driveways and parking up to the 30 percent ceiling even after using the full 20 percent building allowance, but the two figures are tracked separately and both are checked at zoning permit review.

The zoning administrator applies these limits to any new construction, addition or site plan in the district, and the same lot-requirements subsection also sets the district's density sliding scale, which independently limits how many lots a parent parcel can be divided into regardless of coverage.