The office of the commission shall be in Ada county. The office shall always be open, legal holidays and nonjudicial days excepted. The commission shall hold its session at least once in each calendar month, and may also meet at such other times and in such other places as may be expedient and necessary for the proper performance of its duties. For the purpose of holding sessions in places other than the office of the commission, the commission shall have the power to rent quarters or offices, and the expense thereof and in connection therewith, shall be paid in the same manner as the other expenses authorized by this act. The sessions of the commission shall be public.