Beyond terminology : which contracting features promote innovation

Two opposing contracting forms in construction are DB (Design and build) and DBB (Design - bid - build). The first one provides the contractor degrees of freedom in design, which enables innovation. DBB is the safe and traditional contracting form, where the client is responsible for the design and the contractor build accordingly. There is a lack of empirical studies comparing these contracting forms on efficiency and innovation. A first step in comparing is to define and separate the contracts. The straightforward solution is to use the client instigated definitions at face value i.e. a contract is a DB or a DBB according to the client. This is shown to be problematic by using five road construction projects from Sweden. One of the DBB indicates more degrees of freedom in design than a DB contract and only one DB project invites new methods for construction. The paper concludes that contract labelling is not a good proxy for degrees of freedomin design, which is was theoretically drives innovation. This insight facilitates future studies to evaluate contracting forms