Underpinning will devalue a property but by how much will depend upon how severe the subsidence was and also how recently it occurred. As a general estimate underpinned property is worth around 20-25% less. Despite it being worth less, don't let the fact the property has been underpinned put you off.

Is it OK to buy a house that has been underpinned?

It is possible to buy and sell property that has been underpinned, however it can often lead to complications with insurance companies for both the buyer and the seller. Normally, underpinning is required when the structure of a property moves (subsidence) and the foundations need to be repaired.

Can you tell if a house has been underpinned?

The short answer is, is that it can be very difficult to tell if a property has been underpinned from a visual inspection, as the underpinning is concealed below ground and therefore can't always be seen during the course of a typical survey inspection.