(a) Except as provided by Subsection (b), a contract let under this subchapter for the construction of public works or the purchase of materials, equipment, supplies, or machinery and for which competitive bidding is required by this subchapter must be let to the lowest responsible bidder and, as the governing body determines, may be let on a lump-sum basis or unit price basis.
(b) The commissioners court may condition acceptance of a bid on compliance with a requirement for attendance at a mandatory pre-bid conference under § 271.0565.