Flood risk and home insurance: what buyers need to know before they commit

How insurers assess flood risk

Insurance companies use their own flood risk models — often more granular and more up-to-date than the Environment Agency's public data. Two properties on the same road can be assessed very differently if one sits slightly lower or closer to a drainage outlet.

When you apply for insurance, the insurer looks at the postcode and sometimes the specific address, checks their flood risk dataset, and decides whether to offer cover, at what premium, and with what excess.

For medium and high-risk properties, the outcomes vary widely between insurers. Some will refuse to cover flood damage at all. Others will cover it but with a flood excess of £2,500–£10,000 or more — meaning the first £10,000 of any flood claim comes out of your pocket. Others will cover it at near-standard rates, particularly if the property is in the Flood Re scheme.

What flood insurance actually costs

For properties not covered by Flood Re, flood risk can dramatically increase premiums:

• Standard buildings insurance for a low-risk property: £150–£300/year
• Buildings insurance for a medium flood risk property: £400–£800/year
• Buildings insurance for a high flood risk property (no Flood Re): £1,000–£3,000+/year, sometimes with large excesses
• Properties that have flooded previously: can be extremely expensive or uninsurable at standard rates

These figures are rough guides — actual premiums depend heavily on the specific property, its flood history, any resilience measures installed, and which insurer you approach.

Flood Re: the government backstop

Flood Re is a reinsurance scheme backed by the government and funded by a levy on all home insurance policies. It was set up to ensure that households in flood-risk areas can access affordable insurance. If your property qualifies, Flood Re can dramatically reduce both premiums and excesses for flood damage.

Flood Re doesn't sell insurance directly — it operates behind the scenes. Participating insurers can “cede” flood risk policies to Flood Re, which allows them to offer affordable cover even on high-risk properties.

The key exclusions: properties built after 1 January 2009, and leasehold properties where the buildings insurance is arranged by the freeholder rather than the individual. See our full guide to Flood Re eligibility.

What to check before exchange

1. Get at least two insurance quotes for the specific property. Don't estimate — get actual quotes. Use a specialist broker if standard insurers are unwilling to quote (BIBA's find-a-broker tool lists specialists in high-risk properties).
2. Check whether the property qualifies for Flood Re. If it was built before 2009 and you'll be arranging your own buildings insurance (i.e. it's not a leasehold with buildings insurance through the freeholder), it probably qualifies. Confirm with the insurer.
3. Check the excess, not just the premium. A reasonable annual premium with a £10,000 flood excess is not reasonable cover. Understand exactly what you'd be liable for in a claim.
4. Ask whether the property has ever had a flood insurance claim. Previous claims are disclosed to insurers via the Claims and Underwriting Exchange (CUE) database. A history of claims will affect availability and cost.
5. If it's a leasehold flat, check who arranges buildings insurance. If the freeholder arranges a block policy, you may have no control over flood cover — and no access to Flood Re. Ask for details of the current policy and whether it covers flood damage.

The mortgage connection

Your mortgage lender requires adequate buildings insurance as a condition of the loan. If you cannot obtain flood cover — or can only get it with very high excesses — this can affect your mortgage offer. Some lenders specify minimum flood cover requirements.

Alert your mortgage broker to any flood risk concerns early. They can advise on lender-specific requirements and help identify whether the insurance situation will cause problems with the mortgage.

Resilience measures and insurance discounts

Some insurers offer reduced premiums or excesses for properties with flood resilience measures installed — flood doors, air brick covers, raised electrics, flood-proof flooring. If the property already has these, mention them when getting quotes. If you're planning to install them, ask whether the insurer will reduce your premium once they're in place.