Design Bid Build
This is the most traditional process in the U.S construction industry,
where the owner contracts separately with a designer and a contractor.
The design firm is hired to deliver 100 percent complete design documents. The owner or agent then solicits fixed price bids from contractors to perform the work. Designers and contractors bear no actual obligation to one another and the owner bears all risk associated with the completeness of the design documents.
Design and Build
Under this method, an owner typically hires a single entity,
the design/builder, to perform both design and construction
under a single contract.
Portions of all the design and construction may be performed by the entity or subcontract to the other companies.
DB is characterized by high levels of collaboration between the design and construction disciplines, input from multiple trades into the design, and a single entity bearing project risk. Typically, the general contractor is responsible contractually for this delivery method.