subsidence next door - asked to remove hydrangea

[railingsandsilver]

Live in a terraced house in Bristol and have a lovely mature climbing hydrangea on my exterior wall.

Unfortunately my neighbours have bad subsidence (our place is safe, as was underpinned years ago). Their insurers have 'recommended' that we remove our hydrangea - but their monitoring has shown no evidence of hydrangea roots under neighbour's property, and their report specifically says that vegetation couldn't be determined to have caused what's going on. It seems to be precautionary at this stage.

My plan is to say that I don't believe it's necessary to remove it now but if it shows as a clear factor at a later stage we'll reconsider. But I'm a bit spooked by the 'if you don't follow our instructions, we could hold you liable for costs' wording on their letter. I know insurers like to do this to intimidate and can't legally make us do it if it's an unproven cause.

Does anyone have any experience? Do I just hold my nerve? TIA

I would talk to your insurers first. I find in highly unlikely that your plants are taking enough water to cause changes to the soil that would cause a building to collapse - in fact I almost laughed at the idea.

If it can happen though, it's highly likely your insurers will know it's very possible and can advise from there. Also maybe there's a way of insuring your plants so that if the neighbours had work and DID find evidence that your plants were responsible, and therefore try and charge you for the work, insurance would pay up.

Oh how lovely. Every day’s a school day

That they have asked you to remove as they are concerned it’s causing and / or contributing to movement means that if it IS causing damage, you’ll be deemed to have the required knowledge to enable insurers to pursue you for recovery of the costs they incur in repairing the damage that occurs from now (or from whenever you were asked to remove).

So yes you could be liable in the future.

You’re officially on notice that it is thought that your hydrangeas are contributing to movement. If it proves to be the case at a later date then yes you’d be liable for the damage that can be directly linked to them. If they’d proved that your hydrangeas were causing the current damage - you wouldn’t be liable because you didn’t have the required knowledge when the damage was caused. For future damage you will be deemed to have knowledge.

I’m hoping this makes sense - it’s very hot here!

they think a bush is causing their subsidence? Just laugh at them!!

As a lawyer I’d ignore a lot of the advice here other than contact your insurer. They may not be cover but if you face a claim later and you’ve not notified your insurers, you may struggle to obtain cover.

A bush caused subsidence in my current house. Unless you’re an arborist and have seen the surveys, you’re not really in a position to say!

Not the climbing one and they don't have much of a rootball anyway. Your hydrangea isn't doing any harm. Resist!

That won’t cover you in future because you’re being told someone does think it’s an issue. You can say no and it may never amount to anything but there is a risk that it’ll come back. At which point, it could go beyond just removing the hydrangeas i.e liability for costs of repair (IF they can provide evidence they’re contributing to movement).

They can’t make you remove it
The report offers no evidence your plant has caused any problems
In fact it says quite the opposite

I’d respond with a flat no based on the above
and request that they cease and desist with threatening language

Ps
You’ve had subsidence in the past so it’s not that surprising they have it now. Sounds like the properties are prone to it

Ps

Bristol is prone to

Subsidence Risk: Because Bristol sits on significant clay subsoils, the ground is highly vulnerable to shrinking during long, dry spells. This can result in structural movement or cracks, especially in older buildings with shallow foundations. You can check the specific risk for your exact postcode using the Geobear Subsidence Map Checker.
Garden Challenges: Natural clay soils hold nutrients well but drain poorly, meaning gardens across the area often become waterlogged over wet winters and compacted in the summer

So
Help drainage with gravel directing rain away from your house and prevent soil drying out by watering during dry spells.

Meanwhile as Bristol is prone to subsidence and a hydrangea isn’t a thirsty tree they’ll have an extremely hard time trying to prove you have caused this
Esp as the report doesn't find this

I reckon the people saying “why wouldn’t you remove it” are not gardeners. Of course you don’t remove a beautiful established plant and leave a bare wall
unless you actually have to.

I reckon the people saying to do nothing are gardeners and not lawyers or structural engineers. Of course you don't sit on your hands and risk a silly little plant causing £xxx,xxx of damage that you might end up being liable for.

As other people have said, @railingsandsilver should phone her home insurer.

A Solution apart from watering and draining of course

Prevention: If the plant is indeed the cause,( which an experienced professional would have to prove, plus a SEng )

you may be required to implement mitigation measures,
such as installing a root barrier, radically pruning,
or removing the shrub

Hydrangeas are fairly shallow rooting plants. Even a big one is unlikely to be able to cause subsidence or structural damage. I would do nothing, but maybe offer that you will reduce or remove the plant if a structural engineers report specifically mentions the hydrangea and has proof.

This seems fair enough

@railingsandsilver I almost laughed when I saw it was a hydrangea! It’s a shrub and it’s not like a sycamore or an oak or horsechestnut! It’s highly unlikely it’s caused subsidence.

Yes hydra means water and they like a moist soil but it won’t be seeking water from anywhere near as far as a mature tree would. What mature trees are within 50 ft of the house? Any? What trees do they have?

The other aspect is clay shrinkage and inadequate foundations. Extremely common in pre war houses and certainly in Victorian ones. DH is a structural engineer and it’s really not going to be the fault of a hydrangea.

Who, exactly, has suggested it goes? What qualifications do they have? It’s actually not sensible to remove mature trees either. The water they no longer drink stays in the soil and swells the clay. That can result in heave. So trees need to be managed.

This is their insurance claim. Don’t say anything to your insurers and don’t agree to taking out your plant. The issue is that they are looking for excuses not to underpin. Some idiot thinks removal of a shrub will magically put water back into the soil and push the foundations back up! Dream on! How long have the cracks been monitored? The neighbour should push for underpinning and your shrub stays.

No it doesn’t - the default position for insurers is to demand removal of trees/vegetation “just in case”.

I’d ask for evidence that it is contributing meaningfully to soil shrinkage over and above the general weather conditions.

If it were a tree I’d recommend the OP talk to the local tree officers (even if its not TPO’d) who generally have actual expertise in this area and can advise on likely impact. As its a shrub I’d see if there is someone in the environmental office of the local authority or possibly just try the tree officers. At worst case they will say they can’t help.

We are supposed to be trying to protect trees, shrubs and biodiversity, at the very least they should provide evidence of a problem caused by the planting.

@MeetMeOnTheCorner agree entirely and of course if a shrub or tree is genuinely the cause of shrinking then removal can result in heave.

It is more likely that when you strengthened your foundations that their house became the weak point and now the subsidence you experienced (clay heave I presume) is being expressed in their property.

I’m a lawyer with experience in subs claims. Are you?

I highly doubt your hydrangea is a significant contributor to their issues, even if it drinks a lot. The roots wouldn't affect the foundations. I wouldn't move it.

So not an expert in soil and water management or the causes of subsidence and heave (just as relevant), just part of the machine that makes non evidence based assumptions.

The OP has said they have provided no evidence that the planting contributes to clay shrinkage. If you actually deal with subsidence claims you will know well that this is a common demand “just in case” rather than evidence based. My local tree officer spends a disproportionate amount of time dealing with unnecessary demands to remove all and every bit of sizeable vegetation from loss adjusters who know nothing about soil management.

It's a shallow rooted climber. Of course it isn't contributing to subsidence.

Perhaps get independent horticultural advice/survey on the likelihood that the plant might be causing/worsening the problem by whatever means.
You then have clear guidance as to what to do and if the plant remains on that advice you have documentation for insurers that you undertook a proper survey and acted in accordance with that.