One in six properties affected by flood risk by 2050, study shows

A new study has warned that one in six properties in England will be affected by flood risk by 2050, with the most at-risk homes selling for a third less than unaffected properties.

The report, from Bayes Business School at City University in London, shows how flood risk affects English residential property values.

The report, authored by Alexandros Skouralis and Nicole Lux, predicted that even under an optimistic scenario where emissions are at a low or moderate level, 16.45% of all properties (803,057) in the study’s sample would be exposed to medium or high flood risk by 2050 – around one in six.

If emissions are at a high level, around eight percent of properties would shift from medium to high flood risk by 2050, though the percentage of housing unaffected by flood risk would remain the same.

Using a house price dataset provided by property website Rightmove, the report analyses the 4.8m listings and 3.2m completed transactions that took place between 2006 and 2022.

The study’s data shows that residential properties at risk of flooding are sold at 8.14% lower on average compared to non-affected properties, which reaches as high as 32.2% for the highest risk properties.

For all properties, a property-level flood score was provided by Twinn by Royal HaskoningDHV that considers risk from fluvial, pluvial and tidal sources. It uses advanced flood-modelling techniques and incorporates current hydrology data from the Centre of Ecology & Hydrology. The authors said the model is also used by the major insurance companies.

Key findings from the report include:

• Properties at highest risk of flooding are based in the East of England, Yorkshire and the Humber and the North West, which typically have flood risk probability of between 10% and 12%
• Semi-detached and terraced properties (9% flood risk probability) are more vulnerable to flooding since prevention measures – such as improved windows, doors, vents and pipes – will only be effective in conjunction with neighbours. Detached houses have a 7% flood risk probability
• Overall flood risk is expected to increase for 73% of affected properties by 2080, while the probability of flooding is set to increase by a further 8%
• The value of lower priced properties is likely to be more affected by flood risk when compared to higher priced properties

Dr Lux said the findings should be a wake-up call for risk protection programmes: ‘With sea levels and unpredictability of climate set to rise in years to come, this poses a great threat to properties and the housing market – particularly in low-income neighbourhoods.

‘Flood risk impact on low-income neighbourhoods is something national programmes from the Environmental Agency’s flood risk management plans should take into account.

‘In any case, market participants such as property buyers, insurance companies etc have already accounted for the flood risk in all their underwriting and pricing.’

Ed Burgess, Strategic Manager in Data Services at Rightmove, said: ‘Although flood risk is largely factored into a valuation at the property marketing stage, the analysis shows how it will play a more significant role in property valuations by 2050, and is likely to rise up the list of home-mover concerns.’

Image: Chris Gallagher