The housing investment and mortgage provider found that three million social renters and 1.5 million private tenants do not expect to buy a property.
Meanwhile, of the three million people who do envisage themselves owning a home, half think it will be at least five years before they look to buy.
Earlier this year, Castle Trust carried out research that showed the number of renters in the private sector grown substantially. There were 3.8 million private tenants in 2012, which is an increase of 23 per cent on the 3.1 million figure for 2008.
Sean Oldfield, chief executive officer at Castle Trust, said: “Many people are either unable to get on the property ladder or stuck in their current home, despite interest rates still being at an all-time low.”