Using mortgage brokers to shop around and get the best deal will save time and can save money. Brokers are especially useful if the interest rate is not the only important thing to the homeowner - for example, if they want to borrow additional cash to make home improvements, brokers may seek out the lender that will give them the most money.

Some brokers offer to pay the legal fees if borrowers use their switching services, giving borrowers a greater number of lenders to choose from. NIB, however, has decided not to sell its mortgages through brokers.

Choosing a fixed-rate mortgage can make switching mortgages to a new provider costly, as lenders often charge hefty penalties known as redemption fees if the borrower wants to make an early exit from their fixed-rate contract.

Legal fees for remortgaging can range from €900 to more than €1,500. NIB, Ulster Bank and EBS will pay these fees if borrowers use a solicitor from their panel, while Bank of Scotland Ireland will pay €1,000 toward the cost. NIB will pay €600 if borrowers want to use their own solicitor. At Ulster and EBS, borrowers must not switch again within five years or they will have to reimburse the fees.

NIB will pay either €100 or €150 toward the cost of a property valuation for its banking customers, while Bank of Scotland Ireland pays €150 toward the cost. Every three years, NIB will give customers the opportunity to adjust their interest rate by getting a new valuation done. If their property has gone up in value or they have made a lump sum overpayment, they may qualify for a cheaper interest rate.

Goodbody Stockbrokers believes the pattern of charging lower interest rates to "low risk" borrowers will continue and the gap will widen between these rates and those offered to "high risk" first-time buyers borrowing up to 100 per cent of the property value. So it could be a good idea to seek fresh valuations every few years.