A  survey carried out for the Local Government Association (LGA) by estate agents Savills showed that just 20% of those aged 25 own their own property, compared with 46% two decades ago.
The LGA said social housing was vital to enable families to save for a home.
It asks the government to recognise a "renaissance" in house building by councils is needed.
The LGA said government needed to tackle the shortage of affordable homes to rent and buy. It says it found that, on average, private renters pay 34% of their household income on rent, while social and affordable renters pay 29%.
Homeowners, however, spend an average of 18% of their household income on their mortgage.
But the average size of a deposit to get a mortgage is 62% of annual incomes, or 131% in London.
Lauren Cox is 23 and has just bought a two-bedroom semi on a new estate in Widnes, in Cheshire.
"I'm the first person among my friends to buy a house. I'm pretty proud of it to be honest, because I know how hard it's been for me," she says.
Lauren studied maths at university, and then got a job with accountancy firm Deloitte. But rather than finding a flat, she decided to live with her parents so she could save money.
"I never wanted to rent because I think you just get stuck in a cycle of renting." She cut back on treats like takeaway coffees and made sandwiches to take to work for lunch.
"It really did feel like a sacrifice. When I went out with friends in Liverpool they always went out later and I always had to get the last train home [but] I felt I had to prioritise being sensible and saving."
Her parents charged her a lower than market rate to live at home and, thanks in part to a bursary she received at university, she saved enough for a 10% deposit. The government's help-to-buy scheme has made her mortgage payments more affordable.
Where can I afford to live?
The LGA survey has been released ahead of a government White Paper on housing supply due to be published in January.
Martin Tett, LGA housing spokesman, said it presented an opportunity to boost housing supply and affordability.
"It must recognise that a renaissance in house building by councils will be crucial to helping ensure the mix of homes to rent and buy that are affordable for those people that need them," he said.
"This means powers and funding given to councils to replace sold homes and reinvest in building more of the genuinely affordable homes our communities desperately need."
The LGA wants more power to tell property developers how many affordable homes to include in a development.
In addition, it wants to be able to keep more of the cash raised by selling council houses to reinvest in building new homes.
The association also wants an increase in how much councils can borrow to build new homes.
Responding to the LGA survey, a Department for Communities and Local Government spokesman said: "We've halted the decline in homeownership, with the number of first-time buyers up nearly 60%, and over 335,000 households helped into homeownership through government-backed schemes since 2010.
"Our upcoming Housing White Paper will clearly set out how we plan to build the homes this country needs."
Home ownership among 25-year-olds has fallen by more than half in 20 years, according to council leaders.