Design-build has become the fastest-growing delivery method in the water/wastewater industry across the nation. Cost certainty and accelerated schedules have encouraged most states to embrace the design-build model. In the current market, large-scale design-build projects receive most of the headlines, but design-build can be a perfect fit for your small-scale projects.
Owners choose to use collaborative delivery methods for a variety of reasons. The design-build method provides faster delivery times, more long-term cost savings, better risk management, fewer staffing requirements, and more innovative ideas. According to the Design-Build Institute of America (DBIA), from design to completion, design-build projects are delivered 102% faster than traditional design-bid-build projects.
By working collaboratively, project teams have more flexibility to exercise creativity during the design of a project. Regardless of project size, the team can consider and implement the most innovative and efficient solutions. In many cases, design-build leads to cost savings since construction can begin before the design is completed and owner resources are greatly decreased. According to a study by CII/Pankow, design-build projects average 3.8% less cost growth than a comparably scoped project using design-bid-build.
No project is too small to use the design-build method. It’s an effective way to accelerate schedule and amplify cost savings on either a small emergency project or an operations and maintenance (O&M) repair project.
One of the first steps is to determine which design-build model will work best for your situation—fixed-price or progressive. Fixed-price design-build includes an upfront element of design completion that can take several months to complete while proposers develop their cost and design proposals. Progressive design-build is typically qualifications-based in the proposal stage. The selected design-builder brings documents to the 50% to 90% level, then gives the owner a guaranteed maximum price (GMP) or fixed price depending on the owner’s requirements. The progressive design-build method allows for an even more accelerated schedule because it limits preliminary design work before the design-builder is selected.
Below is a case study of a smaller-scale project where the project team maximized efficiency through fixed-price design-build.
Project: Interior Drainage Stormwater Pump Station
Project Team: City of St. Joseph, Missouri (Owner), Garney (Design-Builder), Snyder & Associates (Engineer)
Value: $4.7 million
The goal of this project was to prevent flooding to local businesses when the gate on an existing 72-inch line was closed to the Missouri River. The original request for proposals called for a 150-foot-by-16-foot concrete tank with a discharge header to pump stormwater into the Missouri River with trailer-mounted pumps that the owner would rent. The location of the project was 15 feet from railroad tracks, 50 feet from the levee, and had high-voltage power lines surrounding the site. It was estimated that there would be one year of permitting before construction could begin at this site.
Garney and Snyder & Associates as a design-build team came up with a plan to relocate the structure from the river to within the city’s existing wastewater treatment plant. An existing 54-inch line that is used to discharge plant effluent during flooding conditions was discovered. The extra capacity of this line meant that there would be room for the stormwater. There was a concrete structure over the existing 72-inch line where water could be intercepted when the gate was closed. The project team took this idea into careful consideration and decided to proceed.
With this change, permits were no longer needed, which allowed the project to be completed under the owner’s budget by $400,000 and 12 months ahead of schedule. Three 4-million-gallons-per-day (mgd) pumps were provided to handle the flows, two mechanical bar screens removed trash, and a SCADA system operated the pump station from the plant control room.
The design-build delivery method allowed the team to change the location of the project. The original design would have required manpower to rent, but the design-build team was able to deliver a fully automated pump station and maintain 12 trailer-mounted pumps around the clock. The result of this process was an exceptional product delivered ahead of schedule and under budget.
In summary, smaller design-build projects allow project teams to focus on the fine details in all aspects of the design. This innovative thinking completely enhances the way owners can envision possibilities for their projects, accelerates project life cycles, and reduces overall costs.