Hi,
Do you have a mortgage on your property, if so who is it with? I am a mortgage broker and also deal with secured loan in certain circumstances. However, it is always advisable to contact your mortgage company for an additional loan if your exisiting mortgage has early redemption penalties or a remortgage if it does not. You will get a much lower rate and if you wish to pay that portion of the loan off over a shorter term you can chose to do this. Due to the sources of your income it important to use a broker so they can determine which companies will accept this without having to approach different lenders and carry out more than one credit check.
Hope this helps.