The membership of the Zoning Hearing Board shall consist of three (3) members appointed by the Board of Supervisors by resolution. Their terms of office shall be three (3) years and shall be so fixed that the term of office of one (1) member shall expire each year. The Board Chairman shall promptly notify Board of Supervisors when vacancies occur. Appointments to fill vacancies shall be only for the unexpired portion of the term. Members of the Zoning Hearing Board shall hold no other elected or appointed office in the Township, nor shall any member be an employee of the Township.