Larry Taylor was told by Nationwide that his home, in Brighton Road, Lancing on the border with Shoreham, was in a category-three flood zone – something he and wife Pauline, 67, were not aware of when they bought their home 17 years ago.
The 72-year-old said: “It’s the highest risk you can get. Yet nobody I know of knows about this.”
Mr Taylor made the discovery during discussions with Nationwide while trying to release equity from his property.
He said: “Why are Nationwide still giving mortgages to people and why are houses still being built, if it’s a high-risk area?
“They are pushing to build more homes in the Adur district.
“Why do they want to build there if it’s ‘category-three’?”
Mr Taylor, a Shoreham Society member, said he had never experienced flooding at his home.
The couple have secured an equity release, which allows home owners to release cash from their home while continuing to live in it, from another provider.
A flood map on the Environment Agency website confirms the area is a category-three flood zone.
And his new knowledge made Mr Taylor question the appropriateness of building new developments in the area – particularly at sites like the nearby New Monks Farm.
However, a spokesman for New Monks Farm Development Ltd said it was important that the development went ahead, as it would ‘improve the situation and protect the wider area’.
The spokesman added: “When the Adur Tidal Wall is built and we have completed our flood defence on the eastern boundary of our site the situation will have improved because the area will then be defended against flood risk.
“We own a number of houses in the area and even before these additional defences are installed we have had no issues or additional premiums imposed on us because of flood risk.”
A spokesman from Nationwide Building Society said: “Unlike a residential mortgage where customers make repayments towards the balance, a Lifetime Mortgage relies on the eventual sale of the property to repay the mortgage balance.
“When assessing an application we conduct a flood assessment using data provided by the Environment Agency.
“As this assessment highlighted that the property was in a category-three flood risk zone and therefore at a high probability of flooding, the application was declined.”