Structural Engineering
The discipline that makes sure a structure can carry its loads safely.
Quick Answer
Structural engineering is the branch of civil engineering that analyzes and designs the load-bearing parts of buildings and other structures. Engineers calculate the forces from gravity, wind, earthquakes, and use, then size members and connections so the structure stays safe and serviceable throughout its life, in line with the governing building code.
The Full Picture
Every structure has to do one job before any other: get its loads safely down to the ground. Structural engineering is the discipline responsible for that. It covers the analysis of forces acting on a structure and the design of the beams, columns, slabs, walls, foundations, and connections that resist them without failing or deflecting excessively.
In a typical building project, the structural engineer of record joins the design team early, works with the architect on a framing concept, and then develops it through schematic design, design development, and construction documents. The output is a set of structural drawings and specifications that show member sizes, materials, reinforcement, connection details, and design criteria.
Design is governed by codes and standards. In the United States, the International Building Code sets the overall requirements and references standards such as ASCE 7 for loads, ACI 318 for concrete, and AISC 360 for steel. Engineers use these to check strength, stability, and serviceability, and local jurisdictions review the design before a permit is issued.
For contractors, structural drawings drive a large share of the cost and schedule of a project. Concrete volumes, rebar tonnage, steel weights, and foundation scope all come from them, and unclear or incomplete structural documents are a common source of RFIs and change orders. Reading them well is a core preconstruction skill even though the contractor does not design the structure.
Real Examples
Common Misconceptions
People assume: The architect designs the structure.
Actually: Architects set the building's form and layout, but a licensed structural engineer designs and seals the structural system. The two coordinate closely, yet the responsibility for structural safety sits with the engineer of record.
People assume: Structural engineering is only about gravity.
Actually: Gravity is only one load. Wind, earthquakes, snow, soil pressure, and temperature effects often control the design, especially for lateral systems and tall or seismic-zone buildings.
People assume: The contractor can substitute members freely if the material is equivalent.
Actually: Any change to a sized member, connection, or material generally needs review and approval from the engineer of record, usually through an RFI or submittal.
Frequently Asked Questions
What does a structural engineer do?
A structural engineer analyzes the loads on a structure and designs the framing, foundations, and connections to resist them safely. They produce sealed structural drawings and specifications, respond to contractor questions during construction, and review shop drawings and submittals.
Is structural engineering the same as civil engineering?
Structural engineering is a specialty within civil engineering. Civil engineering is broader and also includes areas such as geotechnical, transportation, water resources, and site development.
What codes govern structural design in the US?
Most jurisdictions adopt the International Building Code, which references ASCE 7 for design loads and material standards such as ACI 318 for concrete and AISC 360 for steel. Local amendments and state codes can change the specifics.
Do structural engineers need a license?
Yes. Structural design of most buildings must be performed or supervised by a licensed professional engineer, and some states have additional structural engineer licensure for certain building types. Requirements vary by state.