Three out of 10 parents (27%) have at least one adult child, aged between 21 and 40, still living with them at home, said the National Housing Federation. Two-thirds of those parents (66%) said this was because their son or daughter could not afford to rent or buy their own place.
The survey of more than 1,100 parents of adult children found that nearly nine out of 10 people (89%) believe there is not enough affordable housing in the UK.
Chief executive David Orr said: "Empty nest syndrome is becoming a thing of the past. Rather than waving their children off as they grow up and move out, parents are stuck with kids in their thirties still living at home.
"Moving out and setting up a family home of your own is a normal rite of passage. Yet as rents, mortgages and deposits continue to soar out of reach, it is no longer an option for many.
"We're delaying adulthood for grown-ups kids who are left stuck in their childhood bedrooms. As a result, parents are also trapped, unable to move on with their lives and benefit from the freedom which comes when their sons and daughters move out."
The cost of living away from home being too high was blamed by 41%, while 22% said their children were temporarily living at home while they saved up for a deposit.
Mr Orr added: " As a country we need to build more homes at the right prices in the right areas now to ensure there is another option. We must encourage more development of new homes and the decisions about where more homes are built are being made locally, by local councillors.
"They will act if local people say they want more homes in their local communities. Unless local communities speak out in favour of more homes, mums and dads across the country will be stuck providing a roof for their adult children."