Subsidence advice

[BauerTime]

I'm in the process of buying. A house and the environmental survey says subsidence risk is moderate to high, based on the fact that 'some properties in the area may be at risk of subsidence' our homebuyers survey said that the property didn't have subsidence but that the ground material meant that there may be some seasonal movent.

I'm not sure what to make of this other than to check with insurers that the house is not going to have any insurance issues.

Is this anything I need to worry about?

It sounds as though you may have a clay soil - clay shrinks in dry weather and expands in wet. Most of London has clay soil as I understand it. It probably means that insurers in that postcode area assess the subsidence risk as higher in an area with a different soil not prone to seasonal movement when setting premiums. Bear in mind the standard excess for a subsidence claim is 1000. Are there any large trees in the garden or neighbouring gardens or the street outside? The risk subsidence is often higher when there are tree drawing moisture from the soil.

Hi thanks

There are a couple of big trees in the garden yes.

So based on what you have said is it fairly normal to be in a moderate-high risk area in London then? Or have we unearthed a major problem. That's the bit that I don't understand. Is this something we need to possibly reconsider our purchase over or do we need to just make sure we can get insured?

Im guessing if we did have subsidence in the future it would obviously make the house less valuable? But I don't know whether mod-high risk means you will definitely get subsidence in the next 20 years, or the risk is 5% rather than 0.5% (or something like that IYSWIM)

London is on clay so very common I think.

Check the planning permission or building control for the house plus surrounding houses to see if anyone has had their home underpinned.

Ironically, considering the foundations are stronger, etc, insurance companies sonetimes hike the premiums up for houses which have been underpinned.