There are many ways to build a building. The “how” is referred to as the project delivery method. These various methods came about for many different reasons and trends within the building construction industry. Design-build (DB) is one of those methodologies. In the traditional or design-bid-build (DBB) project delivery method (both refer to the same method), it was found that owners started responding to (really, complaining about) the tense relationship between the contractor and the architect. The solution was to combine entities through the DB model.
In the DB model, the architect and the contractor are one contractual entity with the owner. This means that the owner signs only one contract and gets an architect/contractor team. (In the DBB model, the owner contracts the architect and the contractor separately.) Organization aside, what is interesting about this relationship (and deserves introspection, in my opinion) is the role of the architect and, thus, the process of building design. With DB, typically the contractor is the lead as they are “at risk”—they assume the responsibility for and are at risk with construction costs and the like. In this model, the budget can easily set the building design. There are instances where the architect in DBB can be at risk, but it is not advised as architects typically do not have the breadth of experience (and ability/insurance to take on that risk) and construction experience. It is something architects should think about in these contractual relationships.
No two project delivery methods are alike. When deciding which to use, it is important to understand the roles and process and to make sure that it is not only appropriate for the project, but appropriate for the team members involved as well.