Do I Need a Structural Engineer for a Steel Frame Building? | PBE

Steel is a popular choice for warehouses, factories and large-span sheds because it allows long clear spans and fast construction. That does not remove the need for a structural engineer. The steel frame still has to be sized correctly for the loads it will carry, connected safely, and supported on footings suited to the site, and all of that needs to be designed and certified by a registered structural engineer. ## When a Steel Frame Building Needs a Structural Engineer A structural engineer is needed for a steel frame building whenever the structure requires a building permit, which covers the large majority of commercial, industrial and larger residential steel structures in Victoria. This includes new warehouses and factories, portal frame sheds, steel-framed mezzanines, and additions or alterations to an existing steel structure. The only steel structures that may not need engineering input are very small, unengineered garden sheds that fall under a building permit exemption, and even then, a structural check is worthwhile where the shed is close to a boundary or built on sloping or reactive ground. Principal Built Engineering provides [Melbourne structural engineering services](/structural-engineering-melbourne/) for steel frame buildings across the full project range, from small portal frame sheds through to large industrial and commercial structures. ## What a Structural Engineer Designs on a Steel Frame Project Each of these elements interacts with the others. A change to the frame span affects the footing loads, and a change to the bracing layout can affect connection design, which is why steel frame design is carried out as a single integrated structural design rather than a series of separate checks. ## Pre-Engineered Steel Buildings Still Need an Engineer of Record A pre-engineered building (PEB) supplier will typically provide a design for the standard steel components of the building, based on a generic set of assumptions about span and loading. In Victoria, this design still needs to be reviewed and certified by an independently engaged structural engineer, known as the engineer of record, before a building permit can be issued. The engineer of record is also responsible for the elements a PEB supplier's standard design typically does not cover, including the site-specific footing design, connections to any adjoining structure, and compliance with the site's wind and soil classification. ## Steel vs Concrete Framing, and Why the Choice Matters Steel and concrete are the two most common framing systems for commercial and industrial buildings in Melbourne, and the right choice depends on the project.

Factor	Steel Framing	Concrete Framing
Typical span capability	Long clear spans, well suited to warehouses and sheds	Shorter spans without post-tensioning, more common in multi-storey buildings
Construction speed	Faster, off-site fabrication and bolted assembly	Slower, formwork and curing time required
Fire rating	Usually needs applied fire protection for rated elements	Inherent fire resistance in most applications
Site conditions	Lighter structure, often favourable on poorer soils	Heavier structure, may need more substantial footings

A structural engineer will weigh these factors against the site, the building use and the client's program to recommend the framing system best suited to the project, rather than defaulting to one material. ## What Happens Without a Structural Engineer Building a steel structure without proper structural engineering carries real risk. Undersized members, poorly designed connections or inadequate footings can lead to excessive deflection, cracking, or in serious cases structural failure. Beyond the safety risk, a building surveyor will not issue a permit without certified structural documentation, and a builder is exposed if they proceed on an uncertified design. Retrofitting engineering onto an already-built structure is far more disruptive and costly than engaging an engineer before construction starts. Where an existing steel structure is being altered or extended, [structural engineer inspections](/structural-inspections/) of the existing frame are often the first step, so the engineer can confirm what the current structure can support before any new design work begins. ## Frequently Asked Questions If a steel frame project needs structural design or certification of a pre-engineered building, [request a quote](/contact-us/) from Principal Built Engineering.