The Council of American Structural Engineers (CASE) defines a structural engineer as: “An engineer with specialized knowledge, training, and experience in the sciences and mathematics relating to analyzing and designing force-resisting systems for buildings and other structures.” A structural engineer usually has one of two roles on a building project, as identified by CASE:
- The Structural Engineer of Record (SER) “perform[s] or supervise[s] the analysis, design, and document preparation for the building structure and has knowledge of the requirements for the load carrying structural system.” The SER is responsible for the design of the primary structural system, which is “the completed combination of elements which serve to support the building’s self-weight, the applicable live load which is based upon the occupancy and use of the spaces, [and] the environmental loads such as wind, seismic, and thermal.”
- A Specialty Structural Engineer (SSE) “performs structural engineering functions necessary for the structure to be completed and who has shown experience and/or training in the specific specialty.” The SSE “is usually retained by a supplier or subcontractor who is responsible for the design, fabrication, and (sometimes) installation of engineered elements or by the general contractor or subcontractor(s) responsible for construction related services.” Common examples of such elements are precast or tilt-up concrete, open web steel joists, pre-engineered cold-formed steel or wood trusses, and metal building systems.
Every project should have a single designated SER who establishes the structural design criteria and concepts for the project, but may delegate the detailed design of certain portions to SSEs by communicating this information and other requirements on the construction documents (drawings and specifications). In such cases, the SSEs subsequently prepare calculations and construction documents of their own for the delegated work and submit them to the SER, who verifies that they comply with the specified requirements and are consistent with the project as a whole. Without the SER, it is difficult to ensure adequate coordination of design work that is performed by multiple SSEs. This problem often arises in design-build situations when various subcontractors supply their own design services, but there is no SER to review the documents that they produce and harmonize them with each other..