Jeff Stephenson, P.E., is the Team Leader of [...]
Because design-build can come into play in various kinds of site engineering projects, we’ve mentioned it in previous blog posts, but until now we’ve never devoted an entire post to this topic. It’s an important one, especially since design-build is starting to come up more and more in transportation projects as well.
Design-build is a project delivery method that allows the design process to be integrated with the construction process. When a project is bid in a design-build process, the contractor teams with the designers to provide a cost-effective design that meets the constraints identified by the clients. Once the project is awarded, the contractor and designers get underway, and construction may begin while the design is still being completed. This can introduce a level of risk to the contractor by beginning construction while design is still happening, so it is necessary for the designers and contractor to have frequent communication until the design is finished.
We enjoy this collaborative nature of design-build projects because they provide opportunities to work with contractors and find the most efficient design based on the method of construction. This is particularly important in LEED certified projects as the design team, contractor, sub-contractors and commissioning agents all need to collaborate from the very beginning of a project.
Design-build is an alternative to another method of delivery, design-bid-build. With this option, the designers work directly for the owner and prepare a well-defined scope of work which is competitively bid on by the contractor. This process requires time for the design to be fully developed prior to the construction contract being awarded, so in general, it is a longer process.
Because of this, projects with very aggressive schedules are better suited for the design-build delivery method. Projects where the owners require precise knowledge of the finished project from the beginning are more suited for design-bid-build.
Since there are so many benefits to design-build work, it’s not surprising that this method that has traditionally been used in site development is now being utilized on transportation projects as well. As part of a tool called Alternative Technical Concepts (ATCs), many states around the country are using a design-build alternative delivery method, although Alabama currently does not have legislation in place to allow design-build for transportation projects.
The U.S. Department of Transportation has more information about how design-build for transportation projects works, the benefits and costs and a map that shows which states are utilizing this method.