dBB

DBB is an acronym with meanings in several domains, but its most common usage is in construction and project management, where it stands for Design-Bid-Build. In this project delivery method, the design and construction phases are contracted separately, with distinct organizations responsible for each stage.

Under Design-Bid-Build, the owner first hires design professionals (such as architects and engineers) to develop a complete set of design documents. Once the design is sufficiently developed, the project is publicly bid or issued to qualified bidders, and a construction contractor is selected based on bid price and qualifications. The construction work then proceeds under a separate contract to implement the approved design. The design team remains responsible for the design documents, while the contractor manages construction means, methods, and site execution, within the bounds of the contract and design intent.

Advantages of DBB include clear delineation of responsibilities, competitive bidding that can curb costs, and strong owner control over design decisions. Disadvantages often cited are longer project timelines due to sequential phases, a higher potential for change orders when constructability concerns emerge during construction, and reduced involvement of builders early in the design process, which can impact constructability and efficiency. DBB remains common for public sector projects and for owners who prefer straightforward procurement with separate design and build contracts. It is frequently contrasted with alternative methods such as design-build, where design and construction are procured under a single contract, and with other procurement approaches like construction management.

Outside construction, DBB can be used as an acronym in various fields, with meanings that depend on the context.