Hear and decide appeals where it is alleged there is error in any order, requirement, decision, or determination made by an administrative official in the enforcement of this part or of any ordinance adopted pursuant thereto; and

Authorize upon appeal in specific cases such variance from the terms of the ordinance as will not be contrary to the public interest, where, owing to special conditions, a literal enforcement of the provisions of the ordinance will result in unnecessary hardship and so that the spirit of the ordinance shall be observed and substantial justice done.

Meetings of the Board shall be held at least once a month; provided, there is business to transact and at such other times as the Chairman of the Board may determine.

All regular Board meetings shall be open to the public.

The Board shall adopt its own rules of procedure and keep minutes of its proceedings, findings and action in each case and the vote of each member present on each question considered in the proceedings, unless a member disqualifies him or herself.

The presence of four members shall be necessary to constitute a quorum.

Four affirmative votes shall be necessary for granting a variance or appeal.

No proxy vote is permissible.