Some lenders have underestimated the cost of certain home loans - which could threaten the financial system. : UK pension companies may be harbouring billions of pounds of losses from home equity release loans, according to research seen by the BBC. Lenders will lend to older homeowners against the value of their house. They don't repay anything until it is sold. That's fine for the borrower but there are fears firms have underestimated how much these loans could cost them. At least one lender assumes housing will rise 4.25% a year.