Section 663. Meetings

Meetings of the board shall be held at the call of
  the chair and at such other times as the board may determine. The chair,
  or in his or her absence the vice-chair may administer oaths and  compel
  the attendance of witnesses. All hearings before the board shall be open
  to  the  public and shall be before at least three members of the board,
  and a concurring vote of at least three members shall be necessary to  a
  decision  to  grant  an  application or an appeal, to revoke or modify a
  variance, special permit or other decision of the  board,  or  to  make,
  amend  or  repeal  a rule or regulation. The board shall keep minutes of
  its proceedings, showing the vote of each member upon every question, or
  if absent or failing to vote, indicating such fact, and shall also  keep
  records  of its examinations and other official action. Such minutes and
  such records shall be public records.