Construction Delivery Method Comparison: Design-Build vs. Design-Bid-Build

What Is Design-Bid-Build?

The DBB method consists of three phases: 1) the Design phase, 2) the Bid phase, and 3) the Build phase. While the previous point seems obvious, it helps clarify the process.

Design-Bid-Build is a good option for new commercial construction where the owner of the project needs both professional design and construction services while also needing to closely monitor the project, and account for its budget. It’s also a good fit for projects that are required to procure professional design services by qualifications-based selection (QBS) regulations and constructors by competitive bidding.

Although it can be a lengthy contracting process, it allows the designer/architect and general contractor to work directly for the owner but under separate contracts.

The owner works with the design team to develop the necessary contract documents such as, drawings, renderings and specifications. Once the design is finished, it is sent out for GCs to bid on the project. It can take at least 2-4 weeks for contractors and subcontractors to price a project.

The design team and the owner evaluate the bids and determine which GC is best to contract with, and once the contract is finalized, construction starts can be scheduled and material and equipment can be ordered.

The above is a very general and simplified way to look at the Design-Bid-Build method, but for the sake of comparison, it is a good start to understand the idea behind construction contracting.

When Should Design-Bid-Build be Used?

Design-Bid-Build is best for linear project sequences where one step is completed before the next is set to begin. DBB works best for projects where the owner needs complete design control, and for less complicated projects that are budget sensitive but not necessarily time sensitive. Public and municipal entities mostly use this construction delivery method as required by state statutes and is also used by some private developers who are strictly looking for low-cost bids.

What Is Design-Build?

Design-Build helps streamline the project construction process by combining the design and construction phases into a single contract, and by promoting collaboration from beginning to end.

Depending on who the contract is with, DB projects can be architect-led or contractor-led. Architect-led agreements are generally used on projects that have a high complexity of design, such as new buildings or remodels. Contractor-led projects usually don’t rely on difficult design, and involve repetitive work, such as infrastructure projects. Regardless of which way the contract is written, the architect and contractor are usually contractually connected, and one of them is connected to the owner and takes point on the project.

The beginning of the Design-Build process starts with the owner of the project drafting an initial project design and asking for project proposals from various design-builders. These proposals play the role of bids in the DBB method, representing a design-builder’s “best” price for the project at hand. The important difference between a bid and a proposal is that proposals include notes on the project design, while bids don’t alter the project design. Owners typically select the proposal that provides the best value for the project without sacrificing design original design elements.

When Should Design-Build Be Used?

A Design Build contract is ideal when the project owner wants one entity to be responsible for both design and construction. Design-Build is usually the preferred contracting method under a tight schedule. DB contracts are often awarded through negotiation rather than through a bid process.