There’s not much point building new homes if an increased risk of flooding is likely to render them to some degree uninhabitable, suggests new research.

One in nine new homes built in England over the past three years are in flood risk areas, according to analysis by insurer Aviva, prompting the firm to urge the government to take action.

The research shows that 11% of homes constructed between 2022 and 2024 are located in areas currently classed as being at medium or high risk of flooding.

The study combines new address data from the Ordnance Survey with the Environment Agency’s latest national flood risk assessment at constituency level. It identifies 43,937 of the 396,602 new homes recorded in England over the three-year period as being in medium or high-risk flood zones.

More than a quarter – 26% or 101,657 properties – face some level of flood risk.

 

The findings point to a marked increase compared with previous analysis. Aviva’s earlier study, based on government statistics covering 2013 to 2022, found that 8% of new homes were built in flood risk zones – equivalent to around one in 13 properties.

Comparable official figures have not been published since 2022. However, Aviva’s latest assessment suggests that as housebuilding has accelerated, the proportion of new homes in flood-prone areas has also risen.

Jason Storah, chief executive UK and Ireland general insurance at Aviva, said: “We support the government’s plans to build more homes to help drive economic growth. Aviva, as a long-term investor in the UK, has already committed £25bn over the next decade, including into social infrastructure, to support national growth and economic resilience.

“However, this growth needs to be sustainable and it’s vital, therefore, that new homes are built in the right places and with resilience in mind to help homeowners get ready for future impacts.

“As our analysis shows, too many new homes have been built in higher risk areas. It’s particularly worrying that this trend has risen in recent years, just as house building accelerates.

“Importantly, these homes are not protected by the Flood Re scheme, which excludes homes built after 2009 to prevent more new homes being put at risk. Sadly, as the study shows, this simply hasn’t happened.”

Intensifying risk

Aviva’s modelling suggests that the exposure of new homes to flooding will worsen over time as the impacts of extreme weather intensify. By 2050, almost a third, 30%, of homes built in the last three years will be at some level of flood risk by mid-century.

Aviva’s Building Future Communities report, published last October, found that every constituency in Great Britain is projected to have increased flood risk (river, coastal or surface water) in future. In England alone, 69% of constituencies are projected to see an increase of over 25% in the number of properties facing flood risk by mid-century.

The latest analysis also breaks down new-build exposure by constituency and region. It highlights a concentration of at-risk development in parts of the south and east of England.

Almost a third – 32% – of constituencies in Greater London and Essex recorded new homes built in medium or high-risk flood areas between 2022 and 2024. This represents the highest proportion nationally.

Other regions with notable shares of constituencies containing at-risk new homes include Lincolnshire and East Yorkshire at 13%, the North West at 13%, and the West at 13%. The South East recorded 12%, while Yorkshire and the North East stood at 7%. Lower proportions were recorded in the East Midlands at 5%, the West Midlands at 3%, and the East at 2%.

Aviva notes that some areas are inherently more prone to flooding and may face land constraints that make development elsewhere challenging. However, it argues that this increases the importance of embedding property-level flood resilience measures within new schemes.

Storah added: “New housing developments in flood zones can also impact the likelihood of a flood to existing homes in the area. But it is not too late to act. As the government consults on changes to planning regulations, we urge them to strengthen these rules to prevent new unprotected homes from being built in flood zones.

“We believe there should be a presumption against new developments in high-risk areas in the planning rules, alongside mandatory flood resilience measures in building regulations for new homes in areas at risk. This is particularly important in places where surface water flooding is prevalent, which is more difficult to predict and protect against. Property flood resilience does not have to be expensive, and effective measures can be installed for under £1,000.

“In some areas, it will not be a case of if, but when, a home will flood. The strengthening of rules is crucial to ensuring homes are insurable in the future and to protect house values in areas where flooding is predicted. When flooding already costs the UK economy £6bn, where and how we build new homes is a growth issue.”

Aviva’s calls for change:

1. Strengthen planning rules to prevent unprotected development in current and future flood zones

2. Amend building regulations to require low-cost proven property flood resilience (PFR) measures PFR measures are simple, low-cost proven interventions (such as self-closing airbricks) installed in a home to help resist surface water flooding and significantly reduce the amount of time and cost of recovering from a flood

3. Standardise the use of Sustainable Urban Drainage Systems (SuDS) in new developments

3. Mainstream Natural Flood Management (NFM), by revising government funding rules and supporting private finance markets NFM is primarily about slowing the flow of water using interventions like “leaky dams” to provide natural speed bumps for water across the catchment, absorb water, and prevent funnelling water that overwhelms infrastructure downstream.

3. Establish a Resilient Buildings Taskforce to make recommendations on how climate resilience can be placed at the heart of policy and promote cross learning with the insurance, lending, professional and other related sectors

6. Encourage investment and innovations to protect homes against heat risk, including extending Part O Building Regulation requirements to cover refurbishments of existing homes

Main image: Tewkesbury, Gloucestershire, 5 January 2024, local flooding and closed roads due to flood water from the River Avon and Severn and Storm Henk. Credit: Frodo’s Dad/Shutterstock

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