What is subsidence and other types of ground movement?


Subsidence is the downward movement of the site on which a building starts.  Where the movement is unconnected with the weight of the building. Simply put the soil beneath the building foundations is unstable.

This will differ from “settlement” which can also result in the movement of a building.  With settlement the building sinks into the site on which it stands and can be a sign of an inadequate design or construction.  With subsidence the downward movement of the site would have occurred without the weight of the building.

There are other types of movement as well but in real terms ground movement can impact the site on which a building stands, beneath its foundations.  Heave, landslip, settlement and subsidence can cause damage to a property and upset its owners or occupiers.

In insurance policies they often refer to “the site” when talking about movement cover.  This usually means the prepared ground, including made up ground, on which a building is erected after the trenches have been dug, and immediately prior to the first step in the actual process of the building.

Will my insurance company cover me for subsidence?

Yes, they would cover you for subsidence but there are different types of ground movement and four main causes.  These are:-





These are defined as follows:-

Heave – upward movement of the ground beneath a building as the result of soil expanding

Landslip – downward moving of a sloping ground

Settlement – downward movement as a result of soil being compressed by weight of a building within ten years of construction

Subsidence – the ground beneath a building sinks, pulling the property foundations down with it. It usually occurs when the ground loses moisture and strength, which can be caused by a prolonged dry spell.  It may also be caused by trees and shrubs which can absorb significant volumes of water from the soil.

Subsidence – these cases can be complex and can require expert evidence and technical data.  They will need to look at the symptoms of the problem to find out why it is caused.

You would normally find that subsidence is caused by one of the following situations:-

Clay shrinkage

Clay shrinkage is one of the most common causes of subsidence.  Clay is made up of about approximately 30 to 35% water, so soil can with a high clay content dry out as a result of nearby vegetation sapping up water, particular during long hot summers.  The volume of the soil decreases and the buildings foundations subside.


Often a tree can cause structural problems to a property because of the shrinkage of the clay or subsoil beneath the foundations.

An insurance company will usually instruct a company to advise of the most appropriate remedy.  These are called arboriculturalist.  They may include cutting back down the tree to its trunk, topping it, thinning or removing it.  They may also look at installing root barriers to stop the encroachments of the roots.

Escape of water

It is often a case where there has been a significant time of escape of water from a bursting or leaking pipe for example, can wash away fine particulars of underlying soil.  This can happen and the soil beneath the property reduces and the property foundations subside.

An escape of water can cause the underlying soil often to soften.  This will therefore make the whole property have less support and cause the foundations to subside.

When this happens it is often a case that this comes under an escape of water claim within the policy.  It is not unusual for there to be specific exclusions for subsidence damage under this peril clause which could involve a higher excess.


Often this will the case where there has been a collapse of underground mines even long disused mines.  This is a valid insured event but you need to ensure that the property is not necessarily within a mining area and if so that you did disclose this when putting the insurance in place.

Poor Ground

Every property will take a period of time to settle.  This is due to the weight of the building compacting the soil beneath on its foundations.  Unfortunately soil can compact and this can exaggerate due to:-

  1. Poor ground
  2. Inappropriate material used by the builders when making up the ground
  3. Lack of compaction of made up ground material
  4. The way the ground is prepared before the building starts

Any of the above can result in a considerable down movement of the property or floor slabs and damage the property.

It is important that you are aware of any of these circumstances before you take out the insurance policy and that you fully disclose them.

You may find that an insurance company asks you to fill out a specific subsidence questionnaire asking you certain questions before they will give you cover.  These would be items such as to the best of your knowledge are the buildings built on made up ground or landfill or slag heap?

Are there any visible cracks in the walls if yes please advise:-

  1. Between 1mm and 2.5mm wide
  2. Between 2.5mm and 5mm wide
  3. More than 5mm wide

Has the property for which insurance is required ever been damaged by subsidence, heave, landslip or movement and are there any signs of repair?

Are there any trees or shrubs within 20 metres (65 feet) of the property and which are more than 5 metres (15 feet) in height?  If yes please indicate the distance of the nearest shrubs/tree from the building as follows:-

  1. 10 to 20 metres (32 to 65 feet)
  2. Less than 10 metres (32 feet)

To the best of your knowledge has the property ever suffered from any problems with undergrown drainage?

If any of the answers to the above questions are yes then you may have trouble trying to insure the building or alternatively it may be an increased excess for the property.

Would I be covered for all of the above?

Almost all commercial property insurance cover loss or damage by subsidence heave and landslip.  They usually cover the cost of repairing the loss or damage but not the cost of preventing further subsidence.

This means the cost of repairing the damage to the building and super structure is covered but the cost of stopping the building from moving in the future isn’t.

If a building is still moving you will usually need to carry out works to stop the movement first to ensure that the repairs are effective and last for a reasonable period of time.

The insurance company will normally send a loss adjuster to identify the cause of the subsidence and to ensure that its stops the effect on the property by removing vegetation or repairing leaks on drains for example.

You will find that most building policies only the cost of repairing the damage caused by subsidence but not necessarily proactively preventing any future subsidence.

Stabilising the building?

When dealing with this so that the repairs are effective you will need to make sure that the property is stable.  This may not be covered by your insurance but it is needed to be dealt with straight away to stabilize the property to solve the immediate problem and to prevent any future subsidence.

Once the property has been stabilized repairs to the super structure can be carried out.  These can involve filling cracks and restoration begin.  It might even require masonry to be strengthened.


Underpinning if often seen as a permanent and effective way of stabilising a building but is only used in the most serious of cases.  It is seen as a preventative measure which isn’t always covered by your insurance policy.  You would need to check with your insurance company in this regard.

In many cases a building can be stabilized by other action for example:-

Repairing leak drains

Removing vegetation

Removing other external causes

Providing additional strengthening

There are other ways of stopping it and you may need to consider these and what is adequate to stop the movement based on expert advice.

I have an existing subsidence issue from some time ago. What should I do?

Always disclose any form of previous problems you may have had with subsidence and what if any work has been carried out.  This is actually critical when dealing with insurance companies.

You may find that the insurance company would not cover you for any previous work that has been carried out but may cover you in future.

In relation to a claim for subsidence or heave every single property will be different and it is important that you are not only aware of any issues but that they are fully disclosed.

Why not contact us on (01273) 827090 to discuss any requirements you may have. We have insurance companies for all solutions and would be able to help you.