Section 14. Notwithstanding section 39M of chapter 30, for each contract for the construction, reconstruction, alteration, remodeling or repair of a public works project by an awarding authority and estimated by the awarding authority to cost not less than $5,000,000, the awarding authority may utilize design build for the construction, reconstruction, alteration, remodeling or repair of any public works project pursuant to this section and sections 15 to 21, inclusive; but, before using the design build, the awarding authority shall seek the approval of the inspector general pursuant to section 16.