Research compiled by the NHBC Foundation shows that more than 1.8 million households in Britain contain two or more adult generations, yet most homes on the market continue to be built to a traditional family home layout, without consideration for the shift towards multigenerational living.

The NHBC Foundation report: Multigenerational living - an opportunity for UK house builders? outlines the factors behind the trend using statistical analysis as well as interviews with families and major building firms.

The report finds that the number of multigenerational households in the UK increased by 38% between 2009 and 2014, a rise driven largely by the number of adults aged over 25 who live with their parents. In contrast, the number of multigenerational families with grandparents living with them remained static during this period.

Although some people chose this lifestyle out of financial necessity, the report found that there was a variety of reasons why multigenerational households were popular, including pooling resources to buy a larger property, help with childcare and providing support for older family members. Others enjoyed the social benefit of living with more than one generation of their family.

The main findings of the report are:

One survey highlighted in the report suggested that two thirds of people believed the solution to Britain’s ageing population would be to move towards multigenerational living, and yet only 16% said their current house would be suitable. The report suggests how builders could develop layouts suitable for multigenerational living, with self-contained areas for privacy alongside shared communal space.

Multigenerational living is much more established in other parts of the world, such as USA, Singapore and Japan. House builders here have developed specific designs aimed at this sector, such the USA firm which markets a “NextGen” home with the slogan, “For the family you’re raising and the family that raised you”.

Sarah, who took part in the survey and lives with her husband, parents and two young sons, said: “It just works so well for us, the whole family living situation. You’ve got privacy when you want it, you’ve got support when you need it, you’ve got company when you want it. It’s just so fantastic for my kids to be brought up in this environment. I don’t think any of us will have a desire to change it.”

Commenting on the report, NHBC head of research and innovation, Neil Smith, said: “Multigenerational living offers a range of opportunities to house builders, from the targeting of suitable existing home designs to this market, to designing new homes with flexible layouts to suit different household compositions throughout a lifetime.

He added: “Multigenerational living is recognised in other countries as a contributor to improved wellbeing and the more efficient use of housing stock. This report will help us to recognise these benefits as we strive to deliver a modern and relevant house-building programme within the UK.”