53 Pa. Stat. § 16701
Whenever the board of public education of the city of Philadelphia has determined upon the erection of a new school-house, and the councils of the city of Philadelphia have made an appropriation of money to build the same, all matters in connection with the erection of said school-house shall be under the direction of said board of public education, who, immediately after the appropriation is made by councils, shall have a proper plan and specifications of said new school-house prepared; and they shall advertise in at least four of the daily papers of the city of Philadelphia, for not less than one week, for proposals for building said school-house, under the plan and specifications named; said advertisement shall state the time and place at which said proposals shall be opened, at which time and place the proposals made shall be publicly read, and the contract for the building shall be awarded to the lowest bidder within the amount appropriated, proper security being taken for the performance of the terms of contract so awarded.
53 P.S. § 16701