Liability Sharing or Transfer between Design Professionals and Contractors under Various Project Delivery Methods

The high exposure level of architecture and engineering (A/E) professionals to risks and liabilities is well known. The aim of this paper is to provide a clear and comprehensive mapping as to how such professional liabilities (PLs) may be transferred, in part or in full, to contractors under the most prevalent project delivery methods (PDMs), including the design-bid-build (DBB), the construction management at risk (CMAR), the design-build (DB), and the integrated project delivery (IPD) approaches. The research methodology consisted of a number of interrelated steps, starting with a literature review coupled with a case law review of judicial cases and related legal concepts to delineate the main instances where contractors may assume PLs. Liability allocation classes (LACs) were then identified and synthesized to provide a systematic classification of the rationales underlying the liability sharing instances. Qualitative liability split models (LSMs) were also proposed to evaluate the full spectrum of possibilities for the apportionment of PLs. Finally, from the proposed LACs and LSMs, several visual constructs were induced and conceptualized to delineate the main potential liability sharing cases under the relevant PDMs. The findings revealed that the extent of liability sharing will vary within a given PDM and also among the various PDMs. Under DBB, the contractors were found to assume PLs, in part or in full, in 16 out of the 19 schemes identified. This is of significance given that PLs are conventionally seen as assumed by A/E professionals and possibly by owners under this approach. Under the alternate PDMs, it was established that the PLs can potentially be shared with the contractors under all the identified schemes. The higher the integration and collaboration level of the PDM, the more the contractors are implicated in the design and the higher their exposure to PLs is likely to be.