Except as this regulation otherwise provides, an LEA shall use competitive sealed bidding. Quality-Based Selection; Competitive Negotiation; Unsolicited Proposals. An LEA may use quality-based selection or competitive negotiation or accept an unsolicited proposal in order to finance or to speed delivery of, transfer risks of, or otherwise enhance the delivery of public school construction. An LEA intending to use quality-based selection or competitive negotiation or to pursue an unsolicited proposal shall: Present a written determination that the circumstances listed in §B(1) of this regulation exist; and Obtain authorization from the IAC or its designee. An LEA may use intergovernmental cooperative purchasing when the circumstances set forth in Regulation .12B of this chapter exist. Sole Source. If the LEA determines that a competitive source selection method cannot be used because there is only one available source for the subject of the procurement, the LEA may award a contract without competition to the sole source. An LEA intending to use sole source selection shall present a written determination that the circumstances listed in §B(1) of this regulation exist. An LEA may use negotiated award after unsatisfactory competitive sealed bidding when the circumstances set forth in Regulation .14A of this chapter exist.