More than a quarter of 20-34 year old adults currently live at home, while a fifth (19%) of students live with their parents while studying.
In total there are currently 2.7 million households with adult children living at home in the UK, a group the report defined as ‘Full Nesters’.
Nearly a third (62%) of parents support their children financially in such a situation.
Carolyn Fairbairn, chair of the Centre for the Modern Family, said: “As a society, we must make sure that any interventions geared towards helping young adults take their first independent steps in life do not take for granted both the support and sacrifices of their parents.
“For while every Full Nester hopes that their ‘Never Fledged’ offspring will eventually spread their wings and fly, they might find that on their departure they are faced not only with a bare and empty nest, but also radically diminished nest egg with which to secure their financial future.”
To cope with the additional cost of living with their adult children one in three parents (31%) have had to cut down on vital spending such as groceries compared to 21% without children at home.
A third (30%) of Full Nesters have also contributed less to their savings, as more than one in four (28%) has spent their savings to meet the cost of living.