Notwithstanding the provisions of section 48-503, if a natural person or persons own a business building and the land on which same is located which is not sought to be taken and operates a business therein within the proposed district, additional land owned by such person contiguous to the business building containing an area equal to or less than the area occupied by such building shall not be subject to taking by eminent domain without the consent of the owner for the purposes of section 48-503, provided the owner has operated such business on such land for at least one year prior to the adoption of the resolution of intention. The owner shall designate in writing to the council the description of the area which shall not be subject to taking within fifteen days after receiving a written request from the council. In the event the owner fails to designate such area within such fifteen days, then the council by resolution may designate the area to be taken.