The state transportation department building shall constitute the official residence of the state highways and transportation commission. Such building shall be under the charge and control of the board of public buildings, which is directed and empowered to provide for the proper maintenance and repair of said building, and to preserve the same from waste and damage from fire and other causes. The board of public buildings may appoint and employ janitors, elevator operators and watchmen necessary for the proper use, maintenance, management and control of said building. The cost of material, labor and repair necessary for the maintenance and use of said building shall be paid by the state treasurer out of the state highway department fund, upon warrants based upon bills of particulars and vouchers certified by the board of public buildings.