Design and construct (D&C) is an integrated contract form in which a single party — usually a main contractor or a joint venture — is responsible for both the design and the construction of a project. It is closely related to design-build in the United States and to design-and-build in the United Kingdom.
Difference from traditional procurement
In a traditional contract, an architect and/or engineer first produces a detailed specification, and a contractor is then selected to build it. The client carries the design risk.
In design and construct, one party is appointed on the basis of a functional output specification and is responsible for both designing and building. That party carries both the design risk and the construction risk.
Advantages and disadvantages
Advantages:
- Single point of responsibility — for both design and construction
- Speed — design and construction can run in parallel
- Innovation — the contractor can build construction know-how into the design
- Price certainty — usually a lump-sum price for the whole project
- Fewer variations — risks lie with the contractor
Disadvantages:
- Less control — the client has less say in detailing and material choices
- Quality risk — the contractor may cut costs in finishing
- Quality of the brief — an incomplete output specification leads to disputes and extra cost
- Restricted design freedom — for architects and consultants
When to use D&C
Design and construct is often chosen for:
- Infrastructure projects — roads, bridges, tunnels (large public clients regularly use D&C and DBFM)
- Functional buildings — offices, schools, hospitals
- Housing projects — especially larger developments
- Refurbishments — where speed and cost certainty matter most
Variants
D&C belongs to a family of integrated contract forms, including:
| Acronym | Includes |
|---|---|
| D&C | Design + Construct |
| DBM | Design + Build + Maintain |
| DBFM | Design + Build + Finance + Maintain |
| DBFMO | Design + Build + Finance + Maintain + Operate |
With each variant the contractor takes on more services and the contract runs longer.
Related terms
- Specification
- Tender
- Main contractor
- DBFM, DBFMO
- Construction team
- Programme of requirements
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