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Good practice guidance in response to an increase in building claims

James Moorhouse examines the causes and consequences of subsidence, following a spate of claims caused by last year’s hot summer.

The number of subsidence-related claims saw a massive increase in 2018, due to the long dry summer.

Subsidence can occur after a heatwave as the soil underneath building foundations can lose its moisture and shrink, causing a downward movement. This then causes buildings to move, resulting in cracks and damage to the property. Subsidence was first added to UK home insurance policies during the 1970s. This was in reaction to the subsidence surge in 1976, where coverage was previously only available as an optional extra peril. Since then there have been two other major subsidence surges, occurring in 2003 and 2018. During this time, subsidence has become offered as a standard peril on most domestic properties (and even on some commercial properties).

Other factors that can contribute towards subsidence include:

  • Soil type – particularly clay soil as it is vulnerable to changes in weather.
  • Trees and shrubs – some plant life absorbs more water and so can dry the soil out.
  • Local mining activity – old mines and former quarry or pit sites can cause instability if the fill-in material collapses.
  • Leaking drains and water mains.
  • Heave – When the ground beneath a building moves upwards.
  • Landslip/landslide – When the ground beneath a building moves down a slope, taking the property with it.

Subsidence can be identified if sudden large cracks in the walls or ceiling are spotted. Other tell-tale signs include:

  • Diagonal cracks wider at the top than at the bottom.
  • Cracks thicker than a 10p coin
  • Cracks found around doors and windows.
  • Doors and windows sticking for no obvious reason.
  • Wallpaper ripping or crinkling.

Cracks can also occur due to changes in temperature and humidity, or if a new build/extension is still settling under its own weight. Therefore, it needs to be carefully determined whether damage to the property is caused from subsidence or by other means. This is particularly important as general wear and tear
of buildings and poor workmanship are generally excluded from most policy wordings.

Homeowners may find it difficult or expensive to get property insurance after making a subsidence claim. It is expected that the cost of premiums will increase and the customer may now be subject to different terms and conditions in their insurance policy


If a genuine case of subsidence is suspected, an investigation will need to take place to detail the extent of the damage, as well as its source.

Policy wordings will need to clarify what type of investigation is covered, as well as if there are any limits on what can be covered. Once the cause and scale of the subsidence has been established, the insurance policy can be activated and steps can be made towards repairs.

If the damage is superficial, then the cost of repairs would include the expense of having minor cracks filled in and painted over. More serious cracks that have an impact on the structure may result
in walls needing to be re-pointed and repaired with metal fixings.

In extreme cases the house may need to be underpinned, where either existing foundations are strengthened or new foundations are inserted underneath the property, preventing or limiting any further movement. While this used to be standard practice, underpinning is now only used as a last resort. If the damage to the property is so severe that it is uninhabitable, a comprehensive insurance policy should also cover the cost of alternative accommodation while repairs are being carried out.

Homeowners, however, may find it difficult or expensive to get property insurance after making a subsidence claim. It is expected that the cost of premiums would increase and the customer may then be subject to different terms and conditions in their insurance policy. In certain cases, it may no longer be possible to provide continuation of cover. If selling the property, some insurers may be able to continue insuring the property for the new owners. However, all new homeowners are recommended to survey the property before making a decision.


With temperatures rising in the UK, more hot summers are expected. This will also have an impact on more properties as well as existing claimants. There will be a greater need to investigate and action cases of subsidence, as well as preventing subsidence from reoccurring.

Not all subsidence cases can be prevented, however. But preventative measures such as managing trees and shrubs close to the property, and ensuring that gutters, pipes and plumbing are well maintained to prevent leaks, should be recommended. For more information, visit: www.socup.org.uk/87607


  • Trial holes dug to expose the foundations under a building in the area of suspected subsidence.
  • CCTV camera investigation of the drainage system to check for blockages caused by a fractured drain or intrusion of tree roots and vegetation.
  • Monitoring the structure of a property to establish:
  • Extent of future movement.
  • Rate of future movement.
  • Any seasonal cyclical movement.
  • Cause of the movement.
  • If any underpinning is required.
  • Level monitoring readings to determine if there is any continuing movement of the building and how it occurred.
  • Soil samples.
  • Vegetation review.

James Moorhouse is content manager of the CII


Picture Credit | Getty


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