One in five homeowners will extend instead of buying a new home

Half of home owners believe their properties urgently need modernisation to increase its value

One bedroom converted folly dating back to the 1700s to rent, The Gazebo, Friars Lane, Richmond TW9. On with Featherstone Leigh for £2,000 pcm (£462 pw) .

More than 20 per cent of homeowners with growing families will invest in modernising their home instead of moving because they are unable to afford the next step on the property ladder.

The new study from the Federation of Master Builders reveals that a third of homeowners will refurbish their home in the next three years, including new kitchens, bathrooms, home extensions, loft conversions and conservatories.

Homeowners in London are most likely to upgrade for stay-at-home kids who have not yet left the nest, followed by those in Wales and Yorkshire.

"We have seen a rising trend of multi-generational households with grown-up children opting to stay with their parents while they save money for their own homes," said Brian Berry, Chief Executive of the FMB.

The study also shows that:

* Half of home owners believe their properties urgently need modernisation to increase its value

* A quarter of homeowners in London will upgrade to let out spare bedrooms or whole property

* Almost half of homeowners in Northern Ireland feel that they cannot afford to move

In terms of choosing a builder, one in four of the 2,000 people polled find it hard to make a decision. The most common way to choose is via personal recommendation (82 per cent), followed by using trade association websites. However, just over half of those polled were still concerned about being ripped off and nearly a third that the builder would leave before the project was finished.

When picking a builder, reliable references are crucial for two thirds of homeowners, followed by the cost of the quote (61 per cent), a professional manner when quoting and estimating (59 per cent), and whether the firm is a member of a professional trade association (55 per cent).