Design build is a method of project delivery that involves the owner hiring a contractor who in turn hires the designers. The contractor then builds the design made by his sub-contractors.
Like all methods of project delivery there are some problems to be avoided. Design-build works best if there can be a clear statement of requirement and this statement of requirement is unlikely to change. For example design build will work for municipal sub-division development. (Given a street and lot layout, there are not a lot of changes possible in the design of the water and sewer.) It will also work for commercial space. Design and build a store with xx square ft space, ceiling height of xxx ft, lighting levels of xxx etc.
Design build does not work well if the owner does not know what he wants in the first place or if there are a lot of changes in the design or the statement of requirement during the process. If you think that change orders in traditional construction delivery methods are expensive, wait until you start working on design build change orders.
The biggest downfall for design build is in the area of quality control. The normal practice is for the designers to appoint inspectors who are responsible for the testing and on site quality control and have no financial interest in the outcome of these tests. In design build the designers are hired by the contractor who they are expected to control the quality of the final product built by the firm that has hired them. The conflict of interest is clear.
Since quality problems can take some time to show up, the final product may initially look good but in 5 years not be quite as serviceable.
One design-build project that I heard about involved the construction of an elaborate mechanical process. The contractor in an effort to lower his costs used a wide variety of fabricators for the conveyors and other mechanical systems. The result was when they bought the required spare parts the owner had to buy a significant number of different bearings, rollers etc because there was no standardization in the plant.
Design-build does work well for projects with a clearly defined statement of requirement. It can greatly speed up the process. There can be considerable cost savings since the management of the design is in the hands of construction people who know what things really cost.
Some variations are BOM and BOOM (build operate manage and build own operate manage). In these the contract is not for only the construction of the facility but also its on going operation. BOM and BOOM could be used for say industrial effluent treatment. You would have a 20-year contract for xxx volume of effluent with stated properties. It also works for office space development. Instead of the owner going out and building the office, they sign a long-term lease for office space built to their specifications.
Like all other methods of project delivery, design build works best when everyone involved has a good understanding of the process, and of the results that they want to achieve. More important in design build than in design-bid-build is that the owner provides a well thought out statement of requirement that reflects the real needs.
Rick Kitson MBA P.Eng
Construction Project Management
From conception to completion