Except as otherwise expressly provided in this article, this article shall not be construed to require the appointment or reappointment of members of the board of adjustment; instead the present members shall keep and hold their offices until their terms, as set previously, expire, at which time new members shall be appointed or incumbent members reappointed, in accordance with this article. Pending cases shall likewise be governed by the former provisions of this article. (Code 1979, § 8-24)