A House With A History Of Underpinning

A house that has been underpinned carries a history the market reacts to. The reaction is often stronger than the physical evidence justifies.

What the work involves

Underpinning strengthens or extends foundations where the ground beneath has proved inadequate, transferring load to a more stable stratum or spreading it more widely.

It is undertaken in response to movement that has been diagnosed as progressive rather than historic, usually after a period of monitoring.

Because it is expensive and disruptive, it is generally a last resort. Many movement cases are resolved by removing the cause, such as a leaking drain or a tree, without touching the foundations.

Documentation is the asset

A properly executed scheme generates engineer's reports, a specification, building control records, a completion certificate and often a guarantee from the contractor.

That paperwork transforms an unknown risk into a documented event with a diagnosis, a remedy and a date, which is more than most buildings can produce about their foundations.

Its absence is the real problem. A house rumoured to have been underpinned, with no records, is far harder to sell than one with a complete file.

Partial underpinning raises a question

Where only part of a building has been underpinned, the strengthened section and the untouched section may respond differently to future ground movement.

That is a recognised engineering consideration rather than a fault, and schemes are designed with it in mind, but a surveyor will look for evidence at the junction.

A history of repeated repairs to the same building, as opposed to one designed scheme, indicates the underlying cause may not have been resolved.

Insurance follows the claim, not the house

Where the work was carried out under an insurance claim, continuity of cover with the same insurer is often the simplest route, and a buyer can usually ask for it to be transferred.

New insurers may decline, impose a higher excess for movement, or require an engineer's report before quoting, so cover should be confirmed before committing.

Practice varies between markets and changes over time, so a buyer should test the actual availability of cover rather than rely on a general expectation.

What a buyer should establish

The useful questions are what caused the movement, whether that cause was removed, what was done, who designed it and whether monitoring afterwards confirmed stability.

A surveyor should be told about the history before inspecting, because it directs attention to the relevant areas and to the drainage and vegetation that often caused the original problem.

Repaired and documented movement is a different proposition from unexplained cracking, and conflating the two leads buyers to reject the safer of the two houses.