The primary delivery methods for new construction projects in the U.S. have been design-bid-build, design-build and construction manager at risk. But these methods may not always be the best choice for a project.
Design-bid-build is the traditional and most commonly used construction delivery method, accounting for about 60 percent of new construction projects. In these cases, a building owner retains an architect who, in turn, retains subconsultants and engineers to perform the design work to meet the owner's program needs and budget. After the design documents are prepared and completed, the project is put out for bid or the owner considers proposals from contractors based on the design documents. The owner then selects a contractor to construct the building.
Per this traditional approach, the owner contracts separately with the architect and contractor. The architect and contractor have distinct and separate roles and responsibilities. When construction problems arise, there frequently is a dispute that follows this pattern: The contractor believes the problem is a result of inadequate or defective design, and the designer may be critical of the contractor's workmanship, claim the contractor has not complied with requirements in the plans and specifications, or consider the problem to be a function of the "means and methods" chosen by the contractor.