CSI teaches that while project size, nature, and cost all influence the complexity and staffing of a project, the primary determinant of formal roles and responsibilities among owner, design professional, and constructor is the project delivery method.
For example:
In Design-Bid-Build (DBB), the A/E designs under a separate contract with the owner; the contractor is selected later and has no design responsibility (except limited design delegation).
In Design-Build (DB), the design-builder assumes both design and construction responsibilities under a single contract with the owner; the architect is typically under contract to the design-builder.
In Construction Manager at Risk (CMAR), the CM has both preconstruction services and then a construction contract with a Guaranteed Maximum Price.
In IPD, key participants share responsibilities collaboratively, often under multi-party agreements.
Because contracts and relationships change with the delivery method, the Project delivery type (Option D) is what determines how responsibilities are allocated in a formal, contractual sense.
Why the other options are not the best answer:
A. Size of the project – Larger projects may require more staff or additional roles (e.g., full-time construction administrator), but they do not fundamentally change who is contractually responsible for design, construction, and administration.
B. Nature of the project – A hospital vs. a warehouse may influence technical requirements and consultant types, but not the core allocation of responsibilities if the delivery method is the same.
C. Cost of construction – Budget level affects scope and possibly oversight intensity, but not the basic contractual roles of owner, A/E, and contractor.
Key CSI-Oriented References (titles only, no links):
CSI Project Delivery Practice Guide – chapters on Project Delivery Methods and team responsibilities.
CSI CDT Body of Knowledge – “Project Delivery Methods and Their Impact on Roles and Responsibilities.”
