Within the past several years, the water and wastewater industry has advanced design-build— engaging in progressive design-build (PDB), a streamlined procurement method producing remarkable results. A collaborative project delivery method — formerly known as alternative project delivery — PDB is increasing in popularity because of its focus on early team integration, which is becoming more of the norm than the alternative, hence the name change.

Since this procurement method is relatively new for this industry,  many owners have questions.

What is progressive design-build?    

Progressive design-build is a procurement technique that facilitates collaboration between the owner, designer and contractor at the earliest possible stages of the project. In traditional fixed price design-build, a design-builder is procured after the project is largely defined, preliminary design is complete and a prescriptive set of “bridging documents” is prepared. In this model, the owner loses the advantage of the design-builder’s participation early in the decision-making process. These foundational decisions drive project cost, schedule and quality. If the design-builder is not part of fundamental decision-making, then the value of collaboration is significantly diminished.


PDB, on the other hand, provides the means to procure the design-builder early in the process, typically during the conceptual phase of the project. It’s called “progressive” because design progresses with input from all project stakeholders. This process leverages the opportunity for the design-build team to collaborate on the fundamental definition of the project’s scope, cost and delivery schedule. As design evolves, the integrated team can make design decisions within the context of its capital and life cycle cost, maximizing value. With PDB, the project team advances design to a point sufficient to establish a lump sum or fixed price agreement to complete detailed design and construction. This integrated project delivery approach provides built-in safeguards that allow an owner an “off-ramp” at any point prior to formalizing the agreement for detailed design and construction, making sure that cost, schedule and quality meet the project’s overall constraints.

How does the PDB process differ from traditional design-bid-build?

This process greatly differs from design-bid-build (DBB), where the process typically lacks input from construction professionals to accurately predict cost and inform the design process. But upfront, effective and efficient decision-making is just one advantage of PDB when compared to traditional methods. DBIA and the Water Design-Build Council offer a deeper dive into the many benefits of procuring and delivering a capital project from start to finish with an integrated team, which further explains the difference between collaborative delivery methods and traditional DBB.


How is the “team” selected with progressive design-build? 

In the PDB approach, the design-builder — whether an integrated design-build team, a single firm or any combination in between — is predominantly selected on qualifications, experience and presence in the marketplace.

With the project having a basic definition early on, the design-builder, owner and operations staff, and project stakeholders work in a collaborative environment to further define the project. They also develop the basic performance criteria, design criteria, levels of service, quality and cost, keeping financial constraints/project budget at the forefront during the decision-making process.   

Some owners, however, might have requirements within their procurement code that relate to the cost of preconstruction services. If that’s the case, cost for progressive design-build services can be defined for preconstruction services (the progression of design and definition of project scope, schedule and cost). If an owner determines that phase I preconstruction services do not yield a project that meets the project objectives, cost and schedule constraints, then he/she can elect not to go to the second phase (detailed design and construction). Instead, the owner can take an “off-ramp,” stopping the project, which is highly uncommon within the progressive design-build approach.

When the time comes to choose between progressive design-build and the fixed-price model, keep these distinguishing factors in mind:

  1. The procurement process for PDB is quicker and more cost-effective.
  2. Firsthand experience shows there’s better market response and competition with PDB because the cost of entry and/or pursuit is much lower. This results in broader participation for an owner.
  3. Having stakeholders intimately involved in the project from inception offers better value throughout the entire project delivery cycle.

Any other questions about collaborative project delivery? We have answers (and examples) to share.


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