I currently have a Interest Only Tracker Mortgage with Halifax to the value of £123,000. At the moment we are not putting extra money aside as we are currently renovating the house. As the interest rates come down I would like to put the little bit of money saved to good use. Should I open up a savings account to actually pay for the house, or should I overpay on my mortgage? I am able to overpay by 10% a year according to my contract without incurring fees. What do you suggest?