Design-Bid-Build (DBB)

The traditional U.S. project delivery method, which typically involves three sequential project phases: The design phase, which requires the services of a designer who will design the project; the bid phase, when a contractor is procured; and a build or construction phase, when the project is built by the contractor. This sequence usually leads to the sealed bid, fixed price contract.

The owner will select a contractor, usually based on the lowest responsive and responsible bid. The selected general contractor will then execute contracts with subcontractors to construct various specialty items. The contractor is responsible for constructing the facility in accordance with the contract documents. The designer typically maintains limited oversight of the work and responds to questions about the design on behalf of the owner.

In DBB, the owner has more control over the design content, relative to other delivery methods. However, this method typically involves a longer time period to execute, in that construction may not begin until the design and procurement phases are complete. DBB is prone to creating more adversarial relationships between all parties when issues develop, as there is no contractual relationship between the contractor and the designer and no opportunity for collaboration during the design phase.

Design-Build (DB)

A project delivery method that combines architectural and engineering design services with construction performance under one contract.

Under this system, the owner contracts with a DB team, which can be a joint venture of a contractor and a designer, a contractor with a designer as a subconsultant, a designer-led team with a contractor as a subcontracted entity, or a single firm capable of performing both design and construction. Since contractors are most comfortable in the role of risking corporate capital in performing projects, they usually are the lead members of this sort of team.

Construction Management At-Risk (CM@R)

A project delivery method in which the Construction Manager acts as a consultant to the owner in the development and design phases, but assumes the risk for construction performance as the equivalent of a general contractor holding all trade subcontracts during the construction phase. This delivery method is also known as CM/GC.

In addition to providing the owner with the benefit of pre-construction services which may result in advantageous changes to the project, the Construction Management at Risk scenario offers the opportunity to begin construction prior to completion of the design. The CMR can bid and subcontract portions of the work with an approved design at any time, often while design of unrelated portions is still not complete. In this circumstance, the CMR and owner often negotiate a guaranteed maximum price (GMP) based on a partially completed design, which includes the CMR’s estimate of the cost for the remaining design features.

Furthermore, CMR may allow performance specifications or reduced specifications to be used, since the CMR’s input can lead to early agreement on preferred materials, equipment types and other project features. In addition, arrangements can be made regarding risk sharing and profit sharing if there are over-runs or under-runs in the GMP.

Integrated Project Delivery (pureIPD, Lean Construction)

A project delivery method that contractually requires collaboration among the primary parties; owner, designer, and builder; so that the risk, responsibility and liability for project delivery are collectively managed and appropriately shared.

Lean construction principles underlying design and construction are used to drive out waste. Representatives of the three Parties manage the project through consensus decision-making. While the designer retains ultimate design responsibility in accordance with state licensing laws, the constructor and specialty Contractors and suppliers participate in the development of the project design.