16 Pa. Stat. § 8322
Whenever the commissioners of any county are authorized and required to erect a courthouse, jail, or other county building, they shall submit the plans and specifications adopted by them to the judges of the court of common pleas of the proper county for their approval, and when it is obtained they shall let the work by contract to the lowest and best bidder, after three weeks' public notice in two newspapers published in the county, which contract or contracts shall be made subject to the approval of the said judges.
In any county in which the board of commissioners does not levy the taxes for general county purposes, the plans and specifications shall be submitted to and approved by, and the contract or contracts shall be let subject to the approval of, the body which levies the taxes for general county purposes, and submission to or approval by the court of common pleas shall not be required.
16 P.S. § 8322