To carry out the purposes of sections 394.21 to 394.37, the board may employ a planning director and such staff as it deems necessary to assist the planning director in carrying out assigned responsibilities, including but not limited to a zoning administrator, sanitary inspector and a building official. If no planning director is appointed, the board shall designate a chief administrative officer who shall administer the official controls. The board may employ or contract with a planning authority or commission, any agency of the state or federal government, a regional development commission or with planning consultants, or other specialists for such services as it requires.