Almost one in three "millennials" still with live with their families and almost one in 10 say they will never own a home.
The new research, from fund platform Rplan.co.uk, shows that 28% of millennials – those aged between 18 and 34 - still live at home with their parents or caregivers
It followed new analysis from the Office for National Statistics (ONS) that shows young adults are more likely to be sharing a home with their parents than any time since 1996.
There were 618,000 more adults aged between 20 and 34 living with their parents in 2015 than in 1996.
Around one in four young adults lived with their parents in 2015, a total of 3.3 million against 2.7 million in 1996.
Stephen Smith, director, Legal & General Housing Partnerships, said the ONS analysis showed that for the first time in many years, children are not going to be financially better off than their parents.
“As a result, young people are increasingly being forced to postpone their dream of flying the nest, as it is incredibly difficult for them to save for a deposit.
“Wage-growth-beating house price inflation, along with the increasing cost of renting, is eroding people’s ability to save the money they need to get on the property ladder."
Smith called on the Government and housebuilders to develop a strong construction pipeline to ensure that there are enough properties for people to buy.
The Rplan research showed that 40% of millenials still expect to buy their first home by the time they are 30, and another 20% by age 35.
But 31% accept cash from their family to help with the cost of living, taking an average £229.50 a month.
Rplan director Nick Curry said: “Our research reveals the financial difficulties faced by a substantial minority of millennials. It is essential that they are given as much help and incentives to save for their future as possible.
Initiatives such as the Help to Buy ISA for first-time buyers are great but our society needs to look at what more can be done.”