The board shall have charge of the construction, erection, purchase and equipping of any hospital or addition to any hospital and shall employ an architect to prepare the plans and specifications, and to superintend the erection and construction thereof. The architect may be paid out of the proceeds of any bonds issued to provide funds for the erection or construction of such hospital or hospital addition. The architect shall file such plans and specifications, together with an estimate of the cost thereof, under oath, with the secretary of the board. No contract shall be awarded at a price in excess of such estimated costs. After considering and approving the plans and specifications prepared and filed, the board shall advertise for three consecutive weeks, in a newspaper of general circulation in the taxing district of the hospital, for sealed proposals for the doing of such work, in accordance with the plans and specifications therefor, and such contract shall be let to the lowest responsible bidder, the board reserving the right to reject any or all bids. Each bidder shall accompany the bid with a bid bond for 5% thereof issued by a surety company authorized to do business in the state of Kansas or a certified check for 5% thereof payable to the treasurer of the board, as a guaranty that if the contract is awarded to such bidder, such bidder will enter into a contract with the board to perform the same; and if such bidder fails to enter into such contract when awarded, the amount deposited shall be and become the property of the hospital, as liquidated damages, and shall be paid into the operation and maintenance fund of the hospital. The board may require the contractor to give to it a bond guaranteeing the faithful performance of the contract.