Why your project needs a structural engineer

What structural analysis actually is

Before any building project is constructed, engineers must calculate the loads it will encounter (such as wind and weight) and determine how these loads will be distributed throughout the structure. We use mathematics, physics, and computer-aided design (CAD) software to model the behaviour of structures under different conditions and environmental stresses.

This analysis ensures that the materials used — including steel, concrete, timber, or composite materials — are sufficient in strength and durability. Done properly, it also stops a structure being oversized and more expensive than it needs to be.

Codes are not optional

Building codes and Australian Standards exist to protect the people who use a building, and they are not optional.

In practice this is also what makes an approval go smoothly. A certifier assessing a residential project is looking for evidence that the structure has been designed to the National Construction Code and the relevant Australian Standards — site classification under AS 2870, wind classification under AS 4055, and the material standards that follow from the structural system chosen.

When a home project needs an engineer

Anything that changes how load travels through a building is an engineering question: removing a wall, adding a storey, raising a house, extending out, or supporting a new deck off existing framing. So is anything founded on ground whose behaviour is not yet known — which, on a reactive clay site, is most things.

The cheapest time to involve an engineer is before the design is fixed. Long spans, cantilevers and large openings are all easier to resolve on a concept drawing than after a builder has priced the job.