Lump Sum Design-Build (Lump Sum DB)
How it works: One contract is held with the design-builder, who prepares plans and specifications for permitting and construction, hires and manages subcontractors, reviews submittals and shop drawings, procures equipment and builds the project. The owner develops the project with an advisor or bridging consultant up to a 30-percent design level, at which time design-build teams compete to offer the lowest qualified bid. The design-builder then carries out the project to completion according to the specified terms.
Why it works: Lump-sum DB provides accountability for price, time and quality, and the design-builder and owner know project costs at the outset of the desin-build phase. Efficient scheduling and streamlined coordination within the DB team result in cost savings, increased response times and enhanced quality.
What you need to know: Lump-sum DB often boils down to a competition based on price, losing out on the innovation and collaboration that can add so much value to DB projects. Once the design-builder is selected, the owner has little or no transparency into the project as it proceeds. For these reasons, CDM Smith strongly recommends progressive design-build (see below).
The best choice for: Owners who are experienced in alternative delivery; projects that involve building the same design several times (i.e. a series of pump stations).