However, instead of paying interest on the loan, as with most Lifetime mortgages, you agree with the lender to pay a higher sum when the property is sold. This sum is also fixed, ie it cannot rise over time.
When the property is sold the lender must repay the loan and the remainder is their profit.
Obviously if you live a long time this style of Equity Release deal will be more advantageous to you, and better for the lender if you die within a few years signing the paperwork.