Resolutions for the adoption or alteration of plans or specifications, or for the award of contracts, hiring of architects, superintendent, or other employees and the fixing of their compensation, the approval of bonds or bid guaranties, and the allowance of estimates shall be in writing and shall require for their adoption the votes of five members of the building commission, taken by yeas and nays recorded on the journal of the board of county commissioners. When signed by five members of the commission, the county auditor shall draw his warrant on the county treasurer for the payment of all bills and estimates of such commission.