Before taking action on any such appeal, the Board of Appeals shall conduct a hearing at which parties in interest shall have an opportunity to be heard and produce evidence. At least 15 days' notice of the place of this hearing and the time of the hearing shall be given to the appellant by mail at the address specified in his or her appeal petition. In the event that the Board of Appeals shall direct a building permit to be issued after any such appeal, it shall specify the exact location, ground area, height, and other details as to the extent and character of the building, structure, or part for which the permit is granted.