(1) When the ground for erecting any public building shall be designated as indicated in § 14-19-102 [repealed], the commissioner of public buildings shall prepare and submit to the county court a plan of the building to be erected, the dimensions thereof, and the materials of which it is to be composed, with an estimate of the probable cost thereof.
(2) When the plan shall be approved by the court, the commissioner shall advertise for receiving proposals for erecting the building and shall contract with the person who will agree to do the work on the lowest and best terms, not exceeding the amount so appropriated by the court.
(3) The commissioner may let parts of the work to different persons.