Subsidence threat to tree

Campaigning against subsidence claim
London Tree Officer's Association - A guide to risk management strategies for tree related subsidence claims (2024)
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Visit Stop Home Insurers Felling Trees website for some excellent guidance.

Start a campaign!

Get some support from other local residents. Read our guide on starting a local campaign here. 

Is there evidence that the tree is the issue?

How detailed/conclusive is the information that the trees are the cause of the subsidence? Often, trees are implicated in subsidence claims when the issue is not the fault of the tree. Sometimes there is little or no evidence that damage to a property has even occurred. 

Very often, an insurer will ask you to fell trees on your land because it costs them nothing. Your tree may not be the problem. Their letters can be intimidating, but they cannot force you to fell your tree. Make sure you are sure that your tree is the cause of the issue before even considering felling your tree(s). In most cases, there are alternative solutions such as root barriers or underpinning.

If the insurer wants to fell a tree on your land, then you have the right to require them to provide evidence before you decide to act. This information should be sought for trees on public land as well.

We recommend looking at Appendix C of this guide by the London Tree Officers' Association for further information, but generally, here is the sort of evidence you should demand:

Site investigation evidence

  • Crack monitoring records – usually for at least 12 months to show movement matches seasonal soil shrink/swell.

  • Soil analysis – confirming the presence of shrinkable clay or other soil types vulnerable to desiccation.

  • Soil desiccation data -usually for at least 12 months from at least 2 bole holes/trial pits; one with tree roots present and one well removed from the trees. Without this control, it is impossible to distinguish between natural seasonal fluctuations and those caused by trees. The absence of data from a control bole holes/trial pits should be very good grounds for stopping imminent felling.
     

  • Root identification – physical root samples taken to at least foundation depth, with laboratory confirmation of tree genus.

Engineering/structural evidence

  • Reports from a structural engineer showing that the damage pattern is consistent with subsidence caused by root-related soil shrinkage (rather than heave, settlement, or poor construction).

  • Age and design of the building’s foundations – some older properties have shallow or inadequate foundations that make them vulnerable regardless of nearby trees.

  • Elimination of alternative causes (e.g. leaking drains, groundwater changes, or general ground instability).

Arboricultural evidence

  • A report from a qualified arboriculturist assessing the species, size, age, and water demand of the tree, and whether its roots could realistically cause the reported subsidence at that distance and soil depth.

  • CAVAT (Capital Asset Value for Amenity Trees) values for the trees. These can then be set against the costs of engineering alternatives.

  • Consideration of management alternatives – pruning, root barriers, cyclical pruning, root barriers – instead of outright felling.

If you would like to see a great example of all the reports you are able to compile to try and prove that the tree is not at fault in the claim, check out the Expert Evaluation Report put together by campaigners in Wivenhoe.

Is the evidence conclusive?

Get a second opinion and scrutinise the details. Check our guide to greenwashing tactics used by insurers (coming soon!).

Speak to the homeowner and find out what advice they have received. Can this be challenged? Get a second opinion. Take Legal Advice.

Tree volume

Is it over 5 cubic metres of wood? If you think yes, contact the Forestry Commission because they will need a felling licence to fell the tree. You can check if it has one here. Call them on 0300 067 4000.

Trees in private gardens are exempt.

A tree which is 10m tall with a trunk diameter of 30cm could be large enough to require a licence.

Is it on public land?

  • Start a campaign to save the tree! Read our guide on starting a campaign here.
  • Contact the insurer directly, name and shame, look up their environmental policies/pledges - does what they are doing conflict with these? Share this on your social media.
  • Take Legal Advice.
  • Has the Local Authority fulfilled its Duty to Consult? Is it a street tree? There are some exemptions, but it’s not dangerous or dead; the council should have probably consulted before deciding to fell the tree.

Apply for a Tree Preservation Order

  • Read our guide to requesting a TPO. In order to remove a TPO, the landowner will have to go through the planning process. This will give you some time and could expose the issue to your local politicians if you can get the application to your Planning Committee. If you are lucky and have a good Tree Officer, they could help too. Tree Officers are employed by your local authority.