Proportion of new homes built in flood areas rises to one in nine

One in nine (11%) new homes in England constructed between 2022 and 2024 have been built in areas of medium or high risk of flooding, according to new analysis from insurer, Aviva.^[1]

The analysis, which identifies new homes address data combined with the Environment Agency’s latest assessment of flood risk at constituency level^[1], shows there is a worrying upward trend of new homes being built in high-risk areas in recent years. 

The data reveals that out of the 396,602 new homes recorded by the Ordnance Survey in England between 2022 - 2024,^[1] 43,937 are in areas of medium or high risk of flooding. Over a quarter (26%), equivalent to 101,657, new homes have some risk of flooding.

Previous analysis from Aviva^[2], based on government statistics, found that 8% of new homes were built in flood risk zones between 2013 and 2022. Comparable figures have not been published since 2022, however, this new study suggests the number of homes built in flood risk areas has accelerated as house building increases.

The outlook for the future is even more concerning. By 2050, 15%, or one in seven, new homes built between 2022 and 2024 will be at medium or high risk of flooding as the impacts of extreme weather become more acute.^[1]

This is despite homes built since 2009 being excluded from the Flood Re reinsurance scheme which was set up in 2016 to improve the affordability and accessibility of flood insurance to properties in high-risk areas.

Jason Storah, CEO UK & Ireland General Insurance, 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^[3], has already committed £25 billion 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.”

The analysis also reveals that new homes are likely to face a greater risk of floods in future than existing properties. Almost a third (30%) of new homes built in the last three years will be at some risk of flooding by 2050, more than the projections for existing properties (one in four).^[4]

Constituencies at risk

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.

This latest data study also analyses new builds by English constituencies, highlighting the regions which are most likely to face current or future flood risk. Almost a third of the top constituencies with the highest number of new homes built in medium or high-risk areas are in Greater London and Essex.

Constituencies in Lincolnshire, the North West and Western regions also include high numbers of new build homes at risk. Whilst it may be more difficult to prevent new housing developments in some areas, which are naturally more prone to flooding and have less land available for development, it is even more important that these homes are protected by property flood resilience measures.

Storah adds: “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.^[5]

“In addition to the potential financial challenges that homeowners may face, we want to help prevent the trauma and disruption that flooding can bring. We’re calling on Government to publish its own figures on the number of new homes in medium and high-risk flood areas and prioritise the prevention of further at-risk developments.

“Building new homes and locating them in lower risk areas are not mutually exclusive objectives. We must do both if we are to deliver sustainable economic growth and get ready for the future.”

Aviva has produced a series of tables which outline the risks from flooding, subsidence and heat by constituency.

Download a full copy of the Building Future Communities report, including Aviva’s Calls for Change, maps, and more details about the UK landmarks.

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References:

^1. _{The Aviva analysis identifies new homes added to the Ordnance Survey AddressBase dataset each year combined with the Environment Agency’s latest assessment of Flood Risk at constituency. Undertaken in December 2025-January 2026. The Aviva analysis used the Environment Agency's latest assessment of Flood Risk (known as NAFRA2). [↑]}

^2. _{Aviva analysis, undertaken January 2024:}

 _{*House building, UK: permanent dwellings started and completed by country - Office for National Statistics (ons.gov.uk) Table 2b (completed homes)}

_{**Live table 320: National Flood Zone 3: Land assessed as having a 1 in 100 or greater annual probability of river flooding (>1%), or a 1 in 200 or greater annual probability of flooding from the sea (>0.5%) in any year. Flood Zone 3 ignores the presence of flood defences. [↑]}

^3. _{Where we invest in the UK | aviva.com [↑]}

^4. _{Environment Agency | National assessment of flood and coastal erosion risk in England 2024 | gov.uk [↑]}

^5. _{Public First | From risk to resilience report PDF [↑]}

Aviva’s calls for change:

1. Strengthen planning rules to prevent unprotected development in current and future flood zones Over the last decade, 110,000 new homes were built in the highest risk flood zones, equivalent to 1 in 13 new homes built in total. If this trend were to continue, 115,000 of the Government planned 1.5m new homes would also be in the highest risk flood zones. This is evidence that the existing planning rules must be tightened to prevent unprotected development in these areas.

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. Where included in a new home PFR measures are either cost-neutral (e.g. wiring electrical points from above) or low-cost. The additional cost for PFR for a new home is around £1,000.

3. Standardise the use of Sustainable Urban Drainage Systems (SuDS) in new developments In England, developers have the automatic right to connect surface water arising from new homes to the public sewerage system, irrespective of whether there is capacity. Implementation of Schedule 3 of the Flood and Water Management Act (2010) would end this automatic right to connect and provide a framework for the approval and adoption of SuDS paving the way for their widespread use. As it stands, SuDS are used inconsistently and the risk of surface water flooding is increasing significantly.

4. 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. It is a cost effective, but under-utilised part of the UK’s flood resilience strategy. Government has proposed a new flood funding formula which would result in the total government budget spent on PFR, NFM and SuDS increasing from 1% (currently) to 18% of the total budget under the new formula. A common value framework is required for NFM to drive enhanced private investment. The Government can help potential investors deliver this enabling framework.

5. 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 With increasing subsidence, storm, flood and heat risk on the way, a Resilient Buildings Taskforce with appropriate representation from developers, social housing providers, surveyors, architects, insurers and lenders should advise government on how to adapt policy to improve the adaptation of existing and new homes to mitigate these risks.

6. Encourage investment and innovations to protect homes against heat risk, including extending Part O Building Regulation requirements to cover refurbishments of existing homes New cheaper innovations are required to help cool older homes when extreme heat occurs. Part O of the Building Regulations (which applies to new homes) sets out requirements to prevent excessive heat. The Climate Change Committee has recommended extending this requirement to the refurbishment of existing homes to drive the innovations that will help adapt older UK homes.

Enquiries:

Liz Kennett

liz.kennett@aviva.com

07800 692675

Alice Constable

alice.constable@aviva.com

07350 398942