Ohio Rev. Code § 153.21: Building commission.

When the board of county commissioners has determined to erect a courthouse or other county building, or to make an addition to, or to make an improvement of any existing county owned building, the board may appoint four suitable and competent freehold electors of the county, who shall, together with the board, constitute a building commission and serve until the courthouse or other county building, or the addition thereto, or the improvements thereof are completed. Not more than two of such appointees shall be of the same political party.