Va. Code § 15.2-2295.1
"Construction" means the building, alteration, repair, or improvement of any building or structure.
"Crest" means the uppermost line of a mountain or chain of mountains from which the land falls away on at least two sides to a lower elevation or elevations.
"Protected mountain ridge" means a ridge with (i) an elevation of 2,000 feet or more and (ii) an elevation of 500 feet or more above the elevation of an adjacent valley floor.
"Ridge" means the elongated crest or series of crests at the apex or uppermost point of intersection between two opposite slopes or sides of a mountain and includes all land within 100 feet below the elevation of any portion of such line or surface along the crest.
"Tall buildings or structures" means any building, structure or unit within a multi-unit building with a vertical height of more than 40 feet, as determined by ordinance, measured from the top of the natural finished grade of the crest or the natural finished grade of the high side of the slope of a ridge to the uppermost point of the building, structure or unit. "Tall buildings or structures" does not include (i) water, radio, telecommunications or television towers or any equipment for the transmission of electricity, telephone or cable television; (ii) structures of a relatively slender nature and minor vertical projections of a parent building, including, but not limited to, chimneys, flagpoles, flues, spires, steeples, belfries, cupolas, antennas, poles, wires or windmills; or (iii) any building or structure designated as a historic landmark, building or structure by the United States or by the Board of Historic Resources.
Va. Code § 15.2-2295.1