Elderly people who own a large house are being warned it is unrealistic to expect to trade it in for a smaller property and live off the balance.
A study by the Commission for Financial Literacy and Retirement Income, formerly the Retirement Commission, says people seeking to buy a smaller home frequently discover it is hard to find.
Kay Saville-Smith carried out the research and says smaller houses are likely to be as expensive as a larger ones in the same area, so little equity is released.
The research also finds growing numbers of people will never be able to afford to buy a home and will rent all their lives.
But Grey Power says many retirees have no choice but to rely on money from selling their family home to fund their retirement.
President Roy Reid says a good number have never earned enough money to do anything but pay off their mortgage.
"There's a lot of people reaching retirement that have been in low income jobs all their lives, and there's a lot of elderly today that haven't got very much in the way of savings.
"There are a lot who had money invested in development companies (which have) gone bust and they've lost their money."
Mr Reid says it is important to own a home mortgage free as a retiree because it is very difficult to live on superannuation payments while paying rent.