Permanent tsb's OnePlan mortgage product will result in savings for borrowers of thousands of euros compared with repayments on conventional loans.

OnePlan enables homeowners to transfer up to 75 per cent of the value of their homes into a special holding account. Borrowers can then use a chequebook to draw on the money. The loan will be repaid at standard variable mortgage interest rates compared to rates of between 10 and 12 per cent charged by other lenders on traditional loans.

A loan of €5,000 at OnePlan's 4.7 per cent rate of interest over five years will result in a saving of €754.20 compared with a 10 per cent rate over the same period charged by traditional bank loans. And €15,000 over 10 years will result in a saving of €4,958.40 while €30,000 over 10 years will save a borrower €9,915.60.

Permanent tsb's head of marketing, Mr Niall O'Grady, said the facility would enable homeowners easier access to the value of "the biggest asset most people will ever own in their lifetimes".

"Around 84 per cent of adults in Ireland aged between 18 and 34 have a mortgage, yet there has been no real product innovation for 10 to 15 years," he said.

He added that the amount transferred into a holding account for a customer would be pre-approved only on the basis of the borrowers' ability to meet repayments.

The bank estimates that, of the 500,000 mortgage-holders in Ireland, around 5 per cent opt for a remortgage in any given year. The bank believes there is an estimated €75 billion in untapped equity in the Irish residential housing market.

"That gives you an indication of the scope we are talking about," Mr O'Grady said. "We think this is a very significant opportunity".