Design-Bid-Build (DBB) is the most traditional and commonly used project delivery method in commercial construction. It is characterized by a linear process where design, bidding, and construction are executed in distinct phases. Here’s an in-depth look at how Design-Bid-Build works:
1. Process Overview
The DBB method is a three-phase process that separates the responsibilities of design, bidding, and construction:
Design Phase:
- The project begins with the owner hiring an architect or a design team to develop the project’s design and produce a complete set of construction documents (including drawings and specifications). These documents are used to convey the project requirements.
- The design team is responsible for ensuring that the project aligns with the owner’s vision, budget, and any regulatory requirements.
Bidding Phase:
- Once the design documents are complete, the project moves to the bidding phase. The owner solicits bids from qualified contractors.
- Contractors submit their bids, typically with a fixed price, based on the completed design documents. The owner then selects the contractor, often based on the lowest responsible bid.
- This phase is also known as competitive bidding, and it allows the owner to get a sense of market rates for the construction work.
Construction Phase:
- The selected general contractor is then responsible for executing the construction according to the design documents.
- The architect or design team may continue to be involved, acting as a representative of the owner to ensure that construction adheres to the design and quality standards. They often review submittals, perform site inspections, and approve any changes during construction.
2. Team Structure and Relationships
- Owner: The owner is responsible for contracting both the designer and the general contractor separately. They play an active role in overseeing the project through both phases, which can require significant coordination.
- Architect/Designer: The designer is engaged only during the design phase and does not have direct authority over the construction. Their involvement may extend into construction as a representative, but they do not manage construction activities.
- General Contractor: The contractor is brought in after the design is complete and is responsible for carrying out the work based on the plans provided. There is no formal relationship between the architect and the contractor—both report to the owner.
3. Key Features of Design-Bid-Build
- Sequential Process: DBB is linear and sequential. Each phase must be completed before the next begins. This sequence is straightforward but can also be slower compared to more integrated methods.
- Fixed Scope and Budget: Because the design is completed before bidding, the owner has a well-defined project scope and detailed plans. This enables contractors to provide relatively accurate bids, often resulting in a fixed price contract.
- Separate Contracts: The owner has two separate contracts—one with the architect for design services and another with the general contractor for construction services.
4. Advantages of Design-Bid-Build
- Simplicity: The process is familiar and straightforward, making it easy to understand and execute, especially for owners with limited construction experience.
- Price Competition: The competitive bidding process often ensures the project is built at the lowest cost. Since contractors bid on a complete set of plans, they have a clear understanding of what they are pricing.
- Well-Defined Design: Since the design is completed before construction begins, the owner has full control over the design and can ensure that their vision is well-documented.
5. Disadvantages of Design-Bid-Build
- Higher Cost: DBB projects tend to cost more in the long run due to inefficiencies between the pre-construction and construction phases. There tends to be more time spent reviewing, understanding, and refining the plans after initial development due to a lack of “constructability” review early on. This leads to a greater chance of Change Orders and administrative budgets from the Architect and GC.
- Longer Duration: Since DBB follows a linear process, the project may take longer to complete compared to delivery methods that allow design and construction to overlap (e.g., Design/Build). Each phase must be completed before the next begins, which can add significant time.
- Potential for Disputes: The separation of design and construction responsibilities can lead to disputes. The contractor may identify issues in the design that were not apparent during the bidding process, potentially leading to conflicts over change orders and additional costs.
- Limited Collaboration: Because the contractor is not involved during the design phase, opportunities for value engineering or construct-ability input are limited. The lack of contractor involvement in the design phase may lead to issues that could have been avoided with early collaboration.
6. Owner's Role
In a DBB project, the owner has significant control but also carries a larger administrative burden:
- Two Separate Contracts: The owner is responsible for contracting separately with the architect and the general contractor. This means more coordination effort compared to other project delivery methods.
- Dispute Resolution: If disputes arise between the architect and the contractor, the owner is typically in the middle. Since the designer and contractor do not have a direct contractual relationship, the owner may have to mediate disagreements.
- Active Oversight: The owner must stay engaged during both the design and construction phases to ensure that the project progresses smoothly.
7. Applicability of Design-Bid-Build
- Public Sector Projects: DBB is widely used in public sector projects because of its transparent process and competitive bidding, which helps ensure fair pricing and a level playing field.
- Well-Defined Projects: This method works well for projects where the scope is well-defined and unlikely to change. If the project scope is likely to evolve, DBB may become cumbersome due to frequent change orders.
- Risk-Averse Owners: Owners who prefer a well-established process with fixed pricing often choose DBB, as it provides a clear delineation of phases and responsibilities.
Summary
Design-Bid-Build is a traditional project delivery method that works in a linear and sequential manner, involving distinct design, bidding, and construction phases. It offers simplicity, competitive pricing, and well-defined design, but it can result in longer project timelines and a lack of early collaboration between the design and construction teams. Owners with limited construction experience or those seeking transparent competitive pricing often prefer DBB, while projects requiring high efficiency, integration, and flexibility may be better suited to alternative delivery methods.