Almost one in ten people aged between 20 and 40 - equivalent to 1.6 million people - are living with their parents because they cannot afford to rent or buy a home.
The findings, which were taken from a YouGov poll commissioned for the housing and homelessness cvharity Shelter, also reveal 22 is considered the ideal age for young people to move out of their family home.
But with almost a third of first-time-buyers aged over 35, young people face years of private renting or living with their parents before they can hope to get on the property ladder.
The poll also revealed the impact living at home as an adult is having on the so-called boomerang generation:
* 59 per cent of those living at home say developing new relationships is harder because of their living situation.
* 35 per cent say they feel embarrassed to admit they live with their parents.
* 24 per cent say that their relationship with their parents has deteriorated because they live with them.
Campbell Robb, Chief Executive of Shelter, said: "These figures paint a vivid picture of twenty- and thirty-somethings in arrested development, with our housing crisis putting the brakes on their aspirations for the future.
"Our chronic lack of homes that young people can genuinely afford to rent or buy is at the root of the problem."
He concluded: "As rents soar and deposits become even further out of reach, the Government needs to look seriously at how it can meet these young people halfway, and make housing more affordable so that this generation and the next can get on in life."