Design–build (or design/build, and abbreviated D–B or D/B accordingly) is a project delivery system used in the construction industry. It is a method to deliver a project in which the design and construction services are contracted by a single entity known as the design–builder or design–build contractor. In contrast to "design–bid–build" (or "design–tender"), design–build relies on a single point of responsibility contract and is used to minimize risks for the project owner and to reduce the delivery schedule by overlapping the design phase and construction phase of a project. "DB with its single point responsibility carries the clearest contractual remedies for the clients because the DB contractor will be responsible for all of the work on the project, regardless of the nature of the fault".
The traditional approach for construction projects consists of the appointment of a designer on one side, and the appointment of a contractor on the other side. The design–build procurement route changes the traditional sequence of work. It answers the client's wishes for a single point of responsibility in an attempt to reduce risks and overall costs. It is now commonly used in many countries and forms of contracts are widely available.
Design–build is sometimes compared to the "master builder" approach, one of the oldest forms of construction procedure. Comparing design–build to the traditional method of procurement, the authors of "Design-build Contracting Handbook" noted that: “from a historical perspective the so-called traditional approach is actually a very recent concept, only being in use approximately 150 years. In contrast, the design–build concept—also known as the "master builder" concept—has been reported as being in use for over four millennia."
Although the Design-Build Institute of America (DBIA) takes the position that design–build can be led by a contractor, a designer, a developer or a joint venture, as long as a design–build entity holds a single contract for both design and construction, some architects have suggested that architect-led design–build is a specific approach to design–build.