Design-build is a project delivery system where an entity (a construction company) handles the entire design and construction process. The owner enters into a contract with a single contractor. This contract binds the contractor to design and construct the project according to the owner’s instructions and specifications.
In a design-build project, the only contract is with the contractor. The contractor, in turn, hires subcontractors who handle the different aspects of the project.
The strength of design-build is in the coordination. The contractor designs the building and directs the pace of construction. Each subcontractor follows the blueprint given by the contractor, allowing for the smooth development of the project.
Flexibility is an advantage of the design-build system. The contractor can edit to design to suit new developments in the project.
In design-build, the contractor bears the project risk. All the subcontractors answer to the contractor, and this minimizes the owner’s risk.
What is Design-Bid-Build?
Design-bid-build is a project delivery system where the owner or the agency in charge of the project hires the architect and the contractor under separate contracts.
The owner first hires an architect to design the project. The architect submits the complete design documents to the owner, who in turn invites bids from contractors.
The architect and the contractor have no contractual agreement that binds them. The contractor only has to execute his part of the project. The owner bears all the risks associated with the execution of the design.
Design-bid-build allows for a construction management structure where a general contractor oversees the project in a managerial role. This role limits the contractor to the supervision of subcontractors.
The design-bid-build system is suitable for an owner who wants involvement in every aspect of the project. The system allows for greater control of the design and execution.
The Advantages of Design-Build
Because the contractor handles design and construction, the owner assumes less risk. This greater risk is on the contractor, whose experience and expertise the owner relies on for the project.
The design-build system allows for greater coordination. The contractor designs the project and directs the pace at which it moves. All subcontractors answer to the contractor, and everyone follows the approved designs.
Design-build fosters communication and collaboration. Contractors usually work with subcontractors they trust. This trust, many times, grows from years of working together. This relationship makes collaboration easy. Since everyone contributes expert input before the final approval of the design, there is little or no finger-pointing or blaming.
As mentioned earlier, the contractor adjusts the design easily in the light of new development.
In the design-bid-build approach, the owner and the architect wield greater control over the project. A general contractor might even be in the picture to oversee the construction as a manager. The problem with this is the multiple layers of management. It slows the process of decision-making.
In the design-build system, only the contractor makes the decision, making the decision-making process faster.
As a follow-up to the last point, design-build also saves time and cost. Decision-making is fast, giving room for fewer mistakes and saving money in the process. Change orders are minimal as the contractor follows the construction closely from the start.
Because the owner has little involvement in the project, there may be a conflict between what the owner has in mind and what the contractor builds. The contractor could have made changes to the design a few times.
The owner may not be getting the best project. Many contractors like to work with who they know and trust, and this gives little or no room to assess new and better subcontractors.
Quality of work can be an issue with the design-build system. The contractor may rush the project and move to a new one, creating a doubt in the quality of the job done.
The Advantages of Design-Bid-Build
The architect looks out for the interests of the owner. The design expresses what the owner has in mind, and the architect reviews the project to ensure that subcontractors follow specifications.
The owner wields greater control in the design-bid-build process and ensures that the contractors give their best to the project.
There is a competitive bidding process in the design-bid-build system, and this gives the owner the option to select the best person for the job.
Design-bid-build allows the owner to make better decisions about cost. In the bidding phase, contractors offer different prices to the owner.
The design-bid-build process does not give room for quick decision-making. New developments may warrant some adjustment in the design, but this may take time as the owner and architect have to approve changes.
Conflicts are more likely to occur among subcontractors as everyone adopts different systems and work at their pace.
Subcontractors have no input in the design of the project. Thus, when the execution turns out bad, conflict and finger-pointing can be the result.
There is always a tendency for the owner to stick with the cheapest bid. This preference may affect the quality of the job. Experienced and established contractors are not always cheap.