(1) Bidder security shall be required for all competitive sealed bidding for construction contracts when the price is estimated by the local public agency to exceed one hundred thousand dollars ($100,000). Bidder's security shall be a bond provided by a surety company authorized to do business in this Commonwealth, or the equivalent in cash, in a form satisfactory to the local public agency. Nothing herein prevents the requirement of such bonds on construction contracts under one hundred thousand dollars ($100,000) when the circumstances warrant.
(2) Bidder's security shall be in an amount equal to at least five percent (5%) of the amount of the bid.
(3) When the invitation for bids requires that bidder security be provided, noncompliance requires that the bid be rejected, provided, however, that the local public agency may set forth by regulation exceptions to this requirement in the event of substantial compliance.
(4) After the bids are opened, they shall be irrevocable for the period specified in the invitation for bids, provided that, if a bidder is permitted to withdraw his bid before award because of a mistake in the bid as allowed by law or regulation, no action shall be had against the bidder or the bidder's security.