The Aviva flood risk warning has put a new question in front of England’s housebuilding drive: what happens if a home can satisfy the planning system today but becomes increasingly difficult to insure later?
Aviva chief executive Dame Amanda Blanc told the BBC that England was “for sure” building homes that could become uninsurable at some point in the future as flood risk increases. Questioning current building patterns, she said: “That doesn’t seem to me to make sense.”
The Aviva flood risk warning is new, but the figures behind it are not. Aviva first published the underlying analysis on 18th February 2026. That distinction matters because the insurer is not saying 115,000 planned homes are already uninsurable, and the Government has challenged parts of Aviva’s flood-risk analysis.
Aviva flood risk warning turns an old dataset into a new insurance question
The Guardian reported Blanc’s remarks from the BBC’s Big Boss Interview on 29th September. She said the flooding threat was “absolutely increasing” and argued that planners and housebuilders should think more carefully about where new homes are being built.
The concern is not simply whether a property floods today. Insurance depends on a risk remaining capable of being pooled and priced. If repeated flooding becomes close to inevitable at a particular property, Blanc’s point is that conventional insurance becomes much harder to provide on normal terms.
That can matter well beyond the premium. Buildings insurance is commonly required by mortgage lenders, while expensive, restricted or unavailable cover can affect mortgageability, buyer confidence and ultimately saleability. None of that means a home in a mapped flood-risk area is automatically unmortgageable or uninsurable now.
The 115,000 figure is a projection, not new September research
Aviva’s February analysis found that 43,937 of 396,602 new English homes recorded between 2022 and 2024 were in areas it classified as having medium or high current flood risk. That is around one in nine.
Aviva projected that 15% of those recent new homes could be at medium or high risk by 2050. It also said 101,657, or 26%, had some current flood risk. The analysis combined new-address data with Environment Agency flood-risk information.
The much-repeated 115,000 figure comes from a different calculation. Aviva said around 110,000 homes had been built in the highest-risk flood zones over the previous decade. If that historical pattern continued, it estimated that roughly 115,000 of the Government’s planned 1.5 million homes could also be built in the highest-risk areas.
So the 115,000 figure is an extrapolation from past development patterns. The Aviva flood risk figure is not a count of approved homes, it is not a forecast that all 115,000 will flood, and it is not evidence that those homes will all become uninsurable.
Government says Aviva understates the role of flood defences
MHCLG pushed back on the insurer’s analysis when it was first published in February. In its formal response, the department said some of the figures were misleading because, in the Government’s view, they did not properly reflect flood defences already in place.
The department pointed to the Thames Barrier as an obvious example of why being inside a mapped risk area does not necessarily mean a development faces the same real-world exposure as undefended land.
It also said 96% of planning decisions in 2024/25 complied with Environment Agency advice on flood risk, while 99% of proposed new homes in planning applications complied with that advice. The Government said: “We will build 1.5 million homes without compromising on safety.”
Those figures answer a different question from the Aviva flood risk warning. Compliance with Environment Agency advice shows how the planning system is applying current flood policy. It does not guarantee that insurance pricing, climate projections or an individual property’s risk profile will remain unchanged over several decades.
Planning permission and insurance are different tests
The current National Planning Policy Framework is clear that development should be steered towards the lowest-risk locations. Its flood policies require the Sequential Test where it applies, site-specific assessment in higher-risk locations and lifetime safety without increasing flood risk elsewhere.
Our Flood Zones in England guide explains the planning categories and the Sequential Test, while the Planning Geek Flood Risk Assessment guide covers the evidence expected where an FRA is needed. The wider policy sits within the current National Planning Policy Framework.
For planning purposes, the critical questions include whether there are reasonably available lower-risk sites, whether the proposed development is safe for its lifetime, whether access and escape are safe, and whether the scheme increases flood risk elsewhere. Mitigation, drainage, design and defences can all be relevant.
The Aviva flood risk warning sits outside that planning test because insurance works differently. An insurer prices the probability and likely cost of a claim, using its own risk appetite, claims experience and modelling. A planning permission therefore cannot promise that insurance will always be available at an acceptable price, just as an insurer’s warning does not retrospectively make a planning permission unsafe or unlawful.
Flood Re does not provide a safety net for new-build homes
The insurance issue is sharper for modern housing because Flood Re does not cover newer homes. Flood Re is a joint scheme between the Government and the insurance industry which helps keep home insurance available and affordable for properties at higher flood risk. Its eligibility rules generally exclude homes built from 1st January 2009.
That was intended to avoid creating an incentive to keep building new homes in high-risk locations while relying on subsidised reinsurance later. The Aviva flood risk analysis made the same point in February when it called for stronger planning controls and wider use of property flood resilience.
Resilience can reduce damage even where risk cannot be eliminated. Measures discussed by Aviva include self-closing airbricks, electrical fittings located higher on walls and materials that can recover more quickly after flooding. Sustainable drainage, site levels, safe access and wider catchment measures can also be important, although the right response is site-specific.
What the Aviva flood risk warning means for development
For developers, the Aviva flood risk warning makes future insurability a viability issue rather than something to assume planning compliance has settled. On larger schemes, early conversations with flood-risk specialists, lenders and insurers can expose problems before design, land value and infrastructure assumptions become fixed.
For planning consultants, the warning reinforces the value of testing current and future flood sources properly rather than treating the mapped river and sea flood zone as the whole story. Surface water, climate change allowances, access, drainage and residual risk can all influence whether a scheme remains robust over its lifetime.
For buyers, a planning permission and a completed new home are not substitutes for checking insurance. Where flood risk is material, obtaining realistic buildings-insurance terms before committing to a purchase can reveal costs or exclusions that may also matter to a mortgage lender.
The Aviva flood risk warning is therefore best read as a long-term market signal, not a declaration that thousands of new homes are already uninsurable. The planning system asks whether development can be located and designed safely. Blanc’s intervention asks a second question: will the insurance market still be willing to carry that risk as the climate and claims picture changes?
0 Comments