What a pre-purchase structural inspection actually covers

What a pre-purchase structural inspection actually covers

Most buyers get a building and pest report and assume structural assessment is included. Sometimes it is. Frequently the report notes visible cracking, recommends further investigation by a structural engineer, and the buyer is at auction on Saturday.

The two products answer different questions and it is worth knowing which one you are holding.

The difference

A building report is a broad visual inspection covering condition across the whole property: finishes, roofing, plumbing evidence, dampness, timber pest activity. It is wide and shallow by design, and that is appropriate for most purchases.

A structural inspection is narrow and deep. It asks whether the structure is performing, what caused any distress, whether it is ongoing, and what it would cost to correct. It is carried out by an engineer who can assess capacity rather than only describe what is visible.

Most properties do not need the second one. Some absolutely do.

When to get one

Get a structural inspection when the building report flags cracking, movement or deflection. When the property has been altered, particularly where walls have been removed. When it sits on a sloping site, on fill, or near a watercourse. When there is a retaining wall of any height on the property, because retaining walls are expensive and frequently under-designed. When the building is old enough that the footing system predates current standards. And when you intend to add to it, because the structure's capacity to take that addition is worth knowing before you buy.

What it establishes

Whether the distress is structural or cosmetic. Many cracks are neither dangerous nor progressing.

Whether it is active. A building that moved and stabilised twenty years ago is a different purchase to one moving now. This is the question with the largest financial consequence and it usually needs the history, the drainage and the site read together.

The likely cause. Reactive soil, drainage, tree influence, inadequate footing, or a structural alteration done without engineering.

The cost to correct. A range is enough at this stage, but it needs to be a range grounded in what the repair would involve.

The commercial reality

Underpinning a dwelling runs into serious money. Rectifying a failed retaining wall is not far behind. Correcting a wall that was removed without a lintel is comparatively cheap but has to be found.

Against those figures, an inspection is a rounding error, and it is the only one of those costs you choose to incur.

What it will not do

An inspection is non-destructive and non-invasive. It will not find reinforcement corrosion inside a slab, a footing that is undersized but not yet distressed, or a defect concealed behind recent render. It reads the evidence available.

That is not a weakness so long as it is understood. Where something material is suspected but not visible, the report says so and recommends what would establish it.

If you are weighing a property with any of the triggers above, a structural assessment before you bid is the cheapest certainty available. On sites where the ground is the question, pair it with a geotechnical opinion.