How much you could borrow will all depend on the equity in your existing property – this is the percentage of the property owned outright by you. An example, if you bought a house for £700,000 and you have £250,000 left to pay, then the equity you have left is £450,000.
You can usually borrow the money starting £10,000. The more equity you have in your property, the more money you will to be able to borrow. Although this would be depending on your current income as well as your credit rating.