Historic Subsidence house purchase help

[Rupinder]

Good evening

Need some help from some experienced members here, please

I’m looking to purchase a house that have had two historic of silence claims 10 years ago and One 3 years ago

Both claims involved a removal of oak tree each time both within 3 m of the house wall and subsequent monitoring for three years afterwards. There was no underpinning done or any foundation work and certificate certificates of structural adequacy were issued.

There are still trees close to the house that the report from the insurance company recommended not to be allowed to outgrow with the current size and to be reduced by 1.8 m every three years

As there has been no underpinning done the question I have is is it relatively safe to purchase a house in this condition or should I run for the hills? It’s not a cheap house it’s just over 2 million and I want to make sure I don’t make a mistake.

Would it have been better if underpinning had been done or is it better that it wasn’t needed? There are no cracks to the external walls or any internal cracks to the wall walls et cetera

Any help would be greatly appreciated

 

[Old Salt]

If the house costs over £2 million surely you would employ professional surveyors!

 

[Rupinder]

Yes I will, but surveyors have all the usual caveats in their surveys etc and the main question I’m asking is, is it good underpinning wasn’t required or would it have been better to be underpinned

 

[Mottie]

Yes I will, but surveyors have all the usual caveats in their surveys etc and the main question I’m asking is, is it good underpinning wasn’t required or would it have been better to be underpinned

Even so, you are asking strangers on an internet forum. See a specialist and pay for proper advice and surveys.

 

[^woody^]

Underpinning is not a prerequisite of dealing with ground movement.

As for being professionally advised, surveyors/engineers are not fortune tellers so you can't expect any report to tell you what will or won't happen. All you will get is comment on the current condition with as you say, lots of caveats. .

The fact is, the property is a risk. Whether that risk is one you are happy to bear is the the issue. And you will be in for a confusing time the more people you ask.

Also remember that any home insurance to a property with this sort of history may be expensive and/or have limited or excluded cover.

 

[Notch7]

Yes I will, but surveyors have all the usual caveats in their surveys etc and the main question I’m asking is, is it good underpinning wasn’t required or would it have been better to be underpinned

So the cause of the movement on the house is a combination of trees in the zone of influence and shrinkable soil.


Oak trees are high water demand (50+ gallons a day for a mature tree). Removal of a tree just 3 metres away will mean that water is no longer being extracted and that leads to heave.

The question is whether the shrinkable soil is stable in the future assuming no changes in trees nearby…..and that is a very hard question to answer.


If the house is pretty old and it didn’t suffer any movement prior to the oak tree removals, In theory history says it’s quite stable.


I presume the price you negotiate will take the risk into account, so if you are getting say £50k or £100k off the price, then you might consider the risk negated.

Bear in mind insurance might be high, or subsidence a policy exclusion and if this is not going to be your forever home then you will have the same difficulties selling as the current vendors

 

[Ivor Windybottom]

You would forever pay higher home building insurance if it had ever been underpinned. Insurers see it as a risk.

 

[nero44]

Hi,

I can't really advise you what todo and I agree with others to get professional advice (structural survey) if in doubt. I did however wanted to share what we have done in a somewhat similar situation.

We purchased a house last year, and found out that the property had a historic subsidence case:

17 years ago there was an incident of minor subsidence in the property - a crack at the top of the stairs on the first floor - caused by an overgrown willow tree next door. We understand the tree was removed and the crack repaired at a cost of around £3k (no underpinning). The property then traded again in 2012. These owners' purchase survey from 2012 revealed no issue. The previous owners also stated that here has been an increased excess for subsidence and that insurers have previously asked that trees in the garden do not grow beyond 5 metres high before they are lopped.

For our purchase (2023), we have not conducted a structural survey, but just a level 3 one and the surveyor found no issues, but of course mentioned multiple caveats. In the end we decided to take the risk and went for it. I did however check that none of my close neighbours had any large trees. I can also confirm that from an insurance perspective having had a historic subsidence case (despite 17 years back) tarnishes the property and will never go away! I have to pay an excess and will need to continue to do so. It also massively limits your choice of insurers as many decide not to insure. In the end it was a minor issue and I found deal, which was acceptable to me.

hope it helps in your decision making.