The growing popularity of progressive design-build (PDB) delivery over the last decade has been celebrated by owners, contractors, and designers alike throughout the water/wastewater industry. The delivery method has proven beneficial in reducing procurement time and costs, allowing owners to work with a single point of accountability throughout design and construction, and driving innovative and creative technical and design solutions without the limitation of the singularly developed, prescribed solution presented in an RFP.
The PDB approach encourages the owner and design-build team to make decisions together in the best interest of the project throughout design evolution. When construction estimating is conducted simultaneously from the outset of design, the team can evaluate options with insight into what different design features and materials cost, and how each may affect the project schedule, allowing the owner to adjust the design and related scope of work to be within its authorized budget. Collaboratively identifying and mitigating risks and challenges early in the design phase ultimately results in a guaranteed maximum price (GMP) that reflects the actual construction cost, while minimizing change orders later in the project and increasing schedule certainty.
Walsh Construction is currently working on several PDB water and wastewater projects on the West Coast. While our project teams have demonstrated successful adoption of the delivery method, the delivery method requires intentional planning and open communication between the owner and the design-build team for optimal results.
We are continually updating our lessons learned to refine the process and avoid the following pitfalls:
Lack of Early Operator Input. The design-build team must include plant operators in design meetings from Notice to Proceed through GMP development to review plans and specifications and evaluate treatment solutions. Equipment, valves, and instruments must not be selected based on capital costs, but weighted by lifecycle cost, sustainability, standardization with control systems and network, facility layout, performance standards, and ease of maintenance. Although the design-builder cannot guarantee that the operators will get all of their preferred choices, the team will consider their input and recommendations when selecting optimal equipment and materials for the project.
Shortage of Labor and Resources. Skilled labor shortage is a problem in construction regardless of the delivery method. This challenge is compounded in the niche water/wastewater treatment sector, as the work differs from that of building and heavy/highway projects. Maintaining a steady workload allows design-build teams to keep tradespeople employed throughout construction and ideally move crews seamlessly from project to project. For progressive design-build projects, construction begins before design has been finalized. Assembling a skilled “core” crew during Phase 1 pre-construction culminating in the GMP amendment familiarizes tradesmen with the project while performing preliminary work, such as site preparation, excavations, and concrete foundations. While crews complete this work, the design-build staff can leverage the crew’s expertise to solicit input on constructability issues and get buy-in on shared project goals.
Project Delays Without Stakeholder Consensus. A project cannot progress without timely decision-making from authorized owner/stakeholder representatives; the lack of such timely decision-making can result in project delays and cost overruns. During the project chartering session, each stakeholder should identify a designated decision maker. Together, all team members can review the detailed project schedule, develop a timeline for critical design decisions (treatment train options, end user requirements, aesthetics, and architectural finishes), and agree on a formal decision-making procedure to keep stakeholders and the design-build team accountable to the project timeline. As a best practice, it is recommended that the owner and design-build team have a staff member on site daily with authority to make decisions in the best interest of the project.
With careful planning and guidance, and early and continuous communication and collaboration with the right people in the room, PDB fosters a collaborative environment for the design-build team to guide project stakeholders through development and delivery of a high-quality project, with cost certainty and greater client satisfaction.