Some thoughts from Mainmark on subsidence for you;
Summer 2025 was reportedly the UK’s hottest on record, meaning that property payouts from insurers grew dramatically in the following months. According to the Association of British Insurers (ABI), domestic subsidence payouts rose to £307 million in 2025, the highest level on record. But 2025 was not just an anomaly and it is more a reflection of the growing structural and climate pressures.
A large percentage of subsidence claims will be tree-related due to the prolonged dry spells leading to shrinking clay soils as tree roots and vegetation extract any available moisture. In turn, there may be significant ground movement and structural damage to building foundations. Alongside this, ageing UK housing stock, drainage failures and more extreme weather cycles, such as droughts followed by heavy rain, will all play a part in driving up more claims.
The subsidence process can be a complex one. Insurers will need approval from surveyors, ground engineers and local authorities to evaluate the problem. Freya Chapman, (below) Residential Lead at subsidence specialist Mainmark UK, explains how insurers can safely navigate this issue.
The cost challenge for insurers
Tree-related insurance claims are often challenging if the responsibility of managing the tree does not belong to the homeowner. For example, if the resident suspects the subsidence is caused by vegetation managed by a local authority, housing association or neighbour, evidence will need to be gathered to determine the cause. Not limited to roots extracting excessive moisture, tree-related claims may also be due to roots damaging drains and causing soil washout.
Simply removing the tree is not a viable option and could actually destabilise the soil. On top of this. Tree Preservation Orders (TPOs) are placed on trees more than 15 years old, which is another hurdle that insurers must jump over. Therefore, the onus for finding a suitable solution sits fully with the insurer, via loss adjusters and engineers.
The standard claims process is typically time-consuming from initial surveying to payout. It involves soil testing, monitoring the subsidence across several months, through visual inspections, crack and level monitoring and site surveys. The process establishes whether this issue is ongoing or stabilising. But the longer the issue remains untreated, the worse the damage and the higher the repair costs may be.
Insurers must have the necessary knowledge for treating surrounding vegetation. In some cases, homeowners may not be covered for the structural damage under their home policies. This may be due to the initial settlement (when the ground adjusts to support the weight of a new home)
In short, subsidence can pose a jarring headache for insurers. It means longer claim lifecycles along with potential customer disruption and reputational risk. Insurers should aim to use any methods readily available to them to speed up the claims process and ensure issues are resolved quickly.
Moving beyond traditional underpinning
One area of notable concern is insurers opting for cheaper superstructural repairs instead of long-lasting ones. As cheaper alternatives often do not deal with the root cause of the issue, it is highly likely that these claims will end up costing more in the long run.
Traditional underpinning involves the soil being dug out and cementitious material added to extend the existing foundation. While this technique is effective and helps settle a claim, it is expensive and disruptive. Which is why the growth of greener alternatives to treat clay shrinkage, such as resin injection, screw piles and ground stabilisation, come as no surprise.
Resin injection technology, for example, can restore stability to properties affected by subsidence beneath their foundations and can replace the need for traditional underpinning or concrete replacement. The resin expands, compacting weak soils, filling voids and lifting the structure back level.
Alongside this, root barriers are another option to prevent a tree’s roots from spreading. Some root barriers are cementitious, which can be time consuming to implement and are not environmentally-friendly, as well as causing differences in moisture zones. The likes of geotextile-based root barriers using copper though, only require a thinner access point (compared to cement-based alternatives), are less invasive and more sustainable. Copper (Cu2 iONs) is also a compound that tree roots naturally divert away from. This is why insurers should aim to speak with ground engineers that might be developing these new technologies.
The likes of remote sensing technology can help with early detection of soil movement or structural changes and can be used to quickly assess potential subsidence risks. This can result in faster solutions before subsidence gets too severe. Specifying the issue and solution during the first site inspection can avoid multiple site visits in the future or a prolonged monitoring process of more than a year. This will also help insurers comply with Financial Conduct Authority guidelines, that require a response to claims within a reasonable timeframe.
Faster, less invasive repairs could lead to potential claims cost control. If insurers work with their approved suppliers that are familiar with their processes, it can ensure consistency and faster evaluation of the severity of subsidence issues. All of which help limit the potential payouts for their live claims.
Opening our eyes to the bigger picture
The latest climate projections point to widened regional disparities and risk variations of different geohazards across the UK. With mining legacy areas in the North, Midlands and Cornwall regions, water stress in the East and high clay content and persistent hotspot in London and the South East, each region requires a tailored approach. Insurers should therefore prepare an increase in subsidence claims in the years ahead and be ready to implement greener alternatives for less disruptive and quicker fixes.
Subsidence is no longer a niche concern. The £307 million figure for residential payouts should be viewed as a stark warning sign, not just a one-off spike. The answer firmly lies in collaboration between insurers, engineers, planners and regulators.
Be the first to comment