Notwithstanding the provisions of subsection A of § 15.2-2000, subject to the provisions of Article VII, Section 9 of the Constitution of Virginia when applicable, any locality may by ordinance authorize the sale or lease of the airspace over or under any public street, lane, alley or other public right-of-way in such locality owned by it in fee simple; provided, that any building, structure or appurtenance thereto, constructed over any such street, lane, alley or other public right-of-way shall have a minimum clearance of sixteen feet six inches and providing further that nothing herein shall be construed to relieve any such grantee or lessee of such airspace of the liability for negligence on their part. No such ordinance shall be adopted until the governing body has held a public hearing thereon after public notice as provided in § 15.2-2204. In addition, in those public rights-of-way in which the Commonwealth has a prescriptive easement for maintenance and public travel, the airspace shall be conveyed or leased only with the consent, in writing, of the Commissioner of Highways. Should the construction of any building or structure in any such airspace require the relocation of any utility, the cost of such relocation shall be borne by the grantee or lessee.