The commission shall fix a date, time and location for its regular meeting by by-law, or motion passed and recorded in its minutes; providing, that regular meetings of the commission shall be held at least once every three months. Special meetings may be called from time to time as provided by law. The commission may adopt such by-laws for the conduct of its business as it finds necessary. Five members of the commission shall constitute a quorum for the transaction of business. A majority vote of those present at a meeting is required for any action of the commission. The chairman shall vote only when required to break a tie.