(a) At least fifteen days prior to submission of bids pursuant to section 103D-302 for a construction or design-build project with a total estimated contract value of $500,000 or more, and at least fifteen days prior to submission of proposals pursuant to section 103D-303 for a construction or design-build project with a total estimated contract value of $100,000 or more, the head of the purchasing agency shall hold a pre-bid conference and shall invite all potential interested bidders, offerors, subcontractors, and union representatives to attend.
(b) The procurement policy board shall adopt rules under chapter 91 to effectuate this section.