What Is the Engineer’s Role in the Design/Bid/Build (D/B/B) Project Process?

A project has a much higher chance of success when the engineer understands their responsibilities in design, bidding, and administration.

by James E. Dipping, PE, CPD, GPD, LEED AP BD+C, ARCSA AP 

Picture this: you are a new engineer excited about your new job in the architectural consulting industry. You are assigned your first project, and your project manager informs you that the project will be issued for bid in two weeks, with construction in four weeks. “Great!” you say to yourself. Then you pause and think, “But what does that mean? What happens with the drawings and specifications I produce?”

At first it might seem easy to understand your role as an engineer in the construction of a building. You might tell your friends or family that you design plumbing systems and that you determine the routing and size of pipes, select pumps, etc. But how does any of that end up as real piping on a project?

The Construction Specifications Institute (CSI) recognizes many processes in the design and construction of buildings, but the most common is the design/bid/build process. In this article, I will explain where engineers fit in this process, what our responsibilities are in developing drawings and specifications, and how we can keep projects moving and stay out of trouble.

What Is D/B/B?

The design/bid/build (D/B/B) process is the most traditional and widely used process for project delivery. Some fundamental tasks must take place in the D/B/B process, which are:

  • Develop owner project requirements
  • Obtain an architect and engineering design team
  • Develop the design through schematic, DD, and ultimately construction documents
  • Bid the project
  • Construct the project

Owner Project Requirements

An owner’s project requirements (OPR) document is the starting point. An OPR provides the basis from which all design, construction, acceptance, and operational decisions are made. It should be in place prior to the basis of design, commissioning plan, and other commissioning/project documents being written.

The OPR document should precede any design, as the guidance it provides can have a large influence on the design of the building. The OPR is a living document and can change as the design progresses, but it should be prepared very early in the process so the criteria outlined can be followed as closely as possible.

Design Stages

Once the OPR document is established, design can begin. This is the process with which engineers are most familiar. Typically, several stages are involved in the development of drawings. They are:

  • Concept design
  • Schematic design
  • Design development
  • Construction documents

You might be asking, “What about bid and permit issuances?” Those are considered in-progress construction documents because they are part of the ultimate goal of producing construction documents.

The goal of the many stages of design is to engineer a system that meets the applicable codes and performs at the level required to meet the OPR. Each level has industry-standard expectations of progress, but these are not hard and fast rules; many projects end up deviating from these expectations.

As engineers, our responsibility in the D/B/B process is to produce a set of contract documents that allow a contractor to understand the scope of work so a building can be built—nothing more, and nothing less.

Successful and cost-effective construction relies on the architect/engineer (A/E) appropriately communicating the project design to the contractor and other project participants. From project conception through design and construction to facility management, effective communication depends largely on having complete and coordinated construction documents. In the D/B/B delivery method, the A/E executes the design phases and delivers the documents according to the owner-A/E agreement, the “prime agreement.”

How Engineers Fit in This Process

In my career I’ve found that engineers all too often feel obligated to perform duties that fall outside their scope, or they don’t understand who they are contracted with during design and after. With that, engineers should understand two key things:

  • Contractors are contracted to the owner directly.
  • There is NOT any contractual relationship between the A/E design team and the contractors.

Creating Documents

If an engineer has done their scope of work correctly, the contract documents will completely convey the “design scope.” This includes specifying products, equipment, materials, specialties, etc. The bottom line is that the contract documents convey the “end result” of the scope, and do not attempt to specify what the industry considers “means and methods,” which are the responsibility of the contractor.

It is important for engineers to understand that the drawings and specifications are complementary. Proper methods of writing specifications or developing master guide specifications must be employed. Engineers must be sure the information is clear and presented in a concise manner, while being technically correct and complete.

Construction documents are defined as the written and graphic documents prepared or assembled by the A/E to communicate the project design for construction and administer the construction contract. Iterations of the construction documents are also used to obtain permits from the authority having jurisdiction (AHJ). Providing complete, coordinated, and easily readable construction documents that demonstrate code compliance can assist in problem-free AHJ reviews and inspections.


Engineers also assist in the bidding process, which is where contract documents are provided to contractors so they may provide a price or “bid” to perform their scope of work. There are several methods by which contractors can be awarded work. Private and public projects will have different selection processes; however, regardless of the method used to select the contractor in the D/B/B process, the engineer’s role is consistent.

As mentioned above, the contract documents are used to identify the scope. Contract documents are not intended to define who does what. Each project is assigned based on how the general contractor awards scope to subcontractors, trade union preferences, and location and availability of skilled labor.

Engineers are typically asked to participate in the bidding process in the following ways:

  • Attend scope review meetings
  • Provide clarification on any contractor pre-bid RFIs needed to complete the contractor’s bid
  • Review submitted bids from contractors

Once the contractors are awarded, construction documents become contract documents. This happens because the owner engages in an agreement in which the engineer’s construction documents are referenced.

Construction Administration

Once construction begins, engineers step into the construction administration phase. During the construction phase of the project, the engineer is the representative of the owner and is responsible for determining the contractor’s compliance with the contract documents. The engineer is the most qualified for this responsibility because they play a significant role in the development of the complete drawings and specifications.

Typical construction administration duties include:

  • Observing the contractor’s work for conformance with the contract documents. (This does not require a full-time, onsite presence.)
  • Informing the owner of the progress of work and reporting deviations from the contract documents as well as defects and deficiencies observed via scheduled punch lists
  • Observing the progress of work for reviewing and certifying the contractor’s applications for payment
  • Requiring testing if seen to be justified
  • Identifying work (but not stopping work) observed in the field if it does not confirm to the contract documents. Work that is identified as not complying with the code or jeopardizing safety should be escalated as soon as possible.
  • Reviewing and acting on contractor submittals
  • Responding to contractor RFIs

During construction administration it is important to understand that the engineer does not work for the contractor. This is likely one of the most difficult lines to maintain during construction, as contractors often have difficult schedules to maintain and can demand information from the design team through the owner, which makes it feel like you are contracted to them.

If an engineer understands their role in the D/B/B process, it allows for a smooth bidding process and a cleaner construction process. When those are successful, the project has a much higher chance of success.

About the Author

James E. Dipping, PE, CPD, GPD, LEED AP BD+C, ARCSA AP, is the Director of Plumbing Engineering at ESD and has more than 24 years of experience in the plumbing design and construction industries. James’ main responsibilities include training development/engineering standardization, specification maintenance, design programming, project management/team leadership, client relations, and quality control for all of ESD’s market verticals. James is a licensed Professional Engineer in Illinois, Indiana, and Wisconsin. He has spoken at ASPE Tech Symposiums and has published several articles in many industry magazines on various topics related to plumbing engineering.

The opinions expressed in this article are those of the author and not the American Society of Plumbing Engineers.

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