Three in 10 homeowners are now living in intergenerational homes, Barclays Mortgages has revealed.

The lender said the likely causes were millennials moving back in with their parents and an increasingly ageing population.

On average, 23% of homeowners have converted living space into an additional bedroom, with a quarter of respondents making these adaptations within the last two years.

Hannah Bernard, head of Barclays Mortgages, said: “As more of us are living with several generations under one roof, it’s interesting to see how, as a nation, we are adapting our properties to the changing needs of our homes. If you live in a multigenerational home or expect to in the future, it’s important to think about whether you need more space in a new property or if you can simply adapt your home to suit your needs.

“We understand the factors that need to be considered in these circumstances and want to help families stay in control of their finances as they plan for a change in their home – whether it’s a big move, a re-mortgage or home improvements.”

Alongside bedrooms, building outhouses in the garden, ground floor bathrooms and step-free access to the home were all noted as necessary improvements when living in an intergenerational household.

More people are living with adult relatives in cities such as London or Birmingham, with increasing housing costs likely to be a contributing factor. East Anglian residents are the least likely to live with adult family members.