Owners new to commercial construction sometimes ask why they need both an architect and a structural engineer. The short answer: architects and structural engineers have different training, different licenses, and legally distinct scopes of responsibility.
What Architects Are Trained and Licensed to Do
Architects are trained in building design: space planning, code compliance for life safety and accessibility, material selection, aesthetics, and the coordination of all consultants (structural, MEP, civil, landscape). The architect is typically the prime professional on a commercial project. Architectural licensure does not authorize the practice of structural engineering — an architect cannot stamp structural calculations or structural drawings in most U.S. states.
What Structural Engineers Are Trained and Licensed to Do
Structural engineers are trained in the analysis and design of load-carrying systems: how forces move through a building, what size members resist those forces, and how connections transfer load from one element to another. The structural engineer of record designs and takes legal responsibility for the structural system — the foundation, framing, connections, and lateral force-resisting system that keeps the building standing in wind and seismic events.
The Formal Division of Responsibility
On a commercial building permit set, architectural sheets (A-series) are signed by the architect and cover floor plans, elevations, sections, details, finish schedules, and code analysis. Structural sheets (S-series) are signed by the structural engineer and cover foundation plans, framing plans, connection details, and structural notes.
Specific Things Only a Structural Engineer Delivers
- Gravity load design — sizing beams, columns, and slabs to carry dead and live loads to the foundation
- Lateral system design — designing shear walls, moment frames, or braced frames that resist wind and seismic forces
- Foundation design — selecting and sizing spread footings, grade beams, piles, or mat slabs based on soil conditions and structural loads
- Structural calculations — the engineering analysis that backs up every structural member size on the drawings
- Connection details — specifying how beams connect to columns, how shear walls anchor to foundations
- Geotechnical coordination — incorporating allowable bearing capacities, liquefaction risk, and expansive soil data into the foundation design
- Special inspection program — defining which work during construction requires special inspection
Where the Two Disciplines Overlap
The two disciplines must be tightly coordinated because architectural decisions drive structural requirements and vice versa. Column locations, floor-to-floor height, shear wall placement, large openings, and rooftop equipment loads all require negotiation between architect and structural engineer early in design.
Can the Architect Be the Structural Engineer?
In a few states, architects with additional credentials can stamp certain structural drawings for simple residential construction. For commercial buildings, this is not permitted — you need a separately licensed structural engineer or civil engineer practicing structural engineering to stamp and sign the structural documents. Building departments will reject commercial structural drawings stamped only by an architect.
The Bottom Line
The architect designs the building; the structural engineer ensures it stands up. These are complementary but legally distinct roles, each backed by a separate professional license and separate legal accountability. On any permitted commercial project, you need both — and the earlier they coordinate, the fewer expensive surprises appear in plan check or during construction.