Subsidence: due diligence for today and the future

Summer has arrived with a scorching presence and, with climate models predicting that we will experience hotter, drier summers in the future, it gives us a glimpse into what we may experience – including impacts on vulnerable peoples’ health, community infrastructure and in the homes we live in.

Subsidence is a key concern for homeowners.  With drier, hotter conditions, there is an increased likelihood of clay rich soils shrinking, creating downward movement in buildings located on these hazardous soils.

For home buyers, it is therefore important that they have a clear understanding of hazards that may affect their future home. While subsidence may not be an issue everywhere in the UK today, we believe it is an issue that should be taken seriously, particularly as we look into the future.

To date, subsidence searches have looked at historic data to understand if such risks pose a threat to a property address, however with the changing climate, we believe it is vital to instead look forward to model future hazards.

Modelling future hazards for homebuyers

We have undertaken some analysis of our National Ground Risk Model (NGRM): Climate™. This models future climate-related environmental hazards, and it has identified that more than 7.65 million properties in Great Britain could be exposed to medium or high risk of soil subsidence by the 2080s.

This is an increase of over 1.89 million individual properties facing increased hazards as a result of climate change^*1.

Soil shrinkage is worse in clay soils, which are commonly found across the south east of England, and has the potential to move foundations, cracking walls and ceilings, resulting in expensive insurance claims and repair bills.

Our data suggests that more than 5.76 million properties in Great Britain are today exposed to medium or high subsidence risk. This increases to approximately 6.64 million in the 2030s.  Specifically, just over half a million more properties (547,317) could be at high exposure in the next 60 years, compared to today’s figures.

In fact, by the 2050s, our data shows us that over 80 counties across the UK are likely to experience an increased risk of soil subsidence hazard to some degree, moving from low to moderate, moderate to high, or high to very high, as a result of our changing climate.

In particular, additional parts of Middlesex, Hampshire, Berkshire, Hertfordshire and Surrey could move to the highest subsidence hazard classes by the 2050s^*2.

Future Insights from the Climate Report

Last October, the Law Society published a Climate Change Resolution^*3 that outlined the role solicitors can play in addressing the climate crisis, which included a call to action to develop a climate-conscious approach to legal practice.

But what does this mean for property lawyers and conveyancers? We believe there is the potential to help clients understand climate change impacts by providing data insights as part of the conveyancing due diligence process.

Dye & Durham’s market leading Climate Report launched to help property lawyers and conveyancers protect homebuyers’ best interests and make informed, future-facing decisions.

In addition to subsidence, the Climate Report models a range of hazards for individual properties, including coastal erosion, flood risk exposure and extreme winds, over the next 60 years.

The report has been designed to cover both physical hazards and delve into how extreme climate conditions could affect properties over time.

Ultimately, robust climate science indicates that we will see an increased number of hotter, drier summers and wetter winters as a result of our changing climate. These conditions are of real concern as they are likely to result in an increase in both the severity and frequency of climate-related impacts to our homes, infrastructure and, more worryingly, the health of vulnerable members of our communities.

In conveyancing, there is a tendency to look backwards to determine risk levels, however we believe there is a duty of care to start using insight and data to look forward.

If we, as an industry, can increase awareness of climate change and its potential impact on our homes and communities, more people will become engaged and want to understand how this may affect their property in the future and take steps to help mitigate risks posed by the changing climate.

1. Climate change data has been calculated for Unique Property Reference Numbers (UPRNs) in Great Britain, based on a Medium Emissions Scenario (RCP:4.5 Equivalent to 2.4°C global warming by 2100s)
2. Climate change data has been calculated based on a High Emission Scenario (RCP 8.5, Equivalent to 4.3°C global warming by 2100s)
3. https://www.lawsociety.org.uk/topics/climate-change/creating-a-climate-conscious-approach-to-legal-practice