Important things to remeber

The amount that you can borrow is determined by the amount of equity you have.

The equity you have in your home is the difference between the amount that your home is worth and the amount that you still owe on your mortgage. Here's a quick example to help you understand.

Suppose you bought a house for $200,000, and put down a down payment of $20,000. The day that your mortgage closes, your home equity is the same as your down payment - $200,000 (home value) - $180,000 (amount owed on mortgage) = $20,000 (equity). Now imagine that five years have passed, and you've made your payments faithfully. You've paid down $13,000 on your mortgage, and now owe $167,000 on it. Your home's value has increased to $250,000. Your home equity is now $250,000 (home value) - $167,000 (amount owned on mortgage) = $83,000.

Depending on your credit and the housing market, you may find lenders who are willing to lend you up to 125% of your home equity, but it's more common for them to lend 60-80% of home equity. Thus, with $83,000 in equity, you may be able to borrow from $49,800 to $103,750.

The interest rate that you'll be offered is dependent on your credit rating.

As with any other loan, the interest rate on your second mortgage will depend on how good your credit rating is. The better your credit rating, the lower your interest rate will be. You can affect that interest rate by taking the time to clean up your credit before starting to look for a second mortgage.

Shopping around for second mortgage rates is always a good idea.

Don't just take the first second mortgage that you're offered, though. Every lender has different ways of factoring in credit ratings and other factors, so it's definitely to your benefit to shop around and get several loan quotes before making a decision.

It can take several weeks to get a second mortgage approval, but there are ways you can speed up the process.

One of the best things you can do in the interests of speeding up the process of loan approval is to get your own home appraisal before applying for a second mortgage. It's not foolproof, but many lenders will happily take your expert's appraisal rather than pay for one of their own.