I have made a few enquiries about mortgaging the rental property with our current lender Bank of Scotland Ireland & they have informed me that unless we have at least 2 rental properties they do not do buy to let - although they do advertise it on their website - only noting "subject to terms and cnditions". The reason I made the inquiry about switching the mortgage was to cut down on costs, but it appears that even to switch the mortgage from one property, with no other changes i.e. term, amount etc. to another property involves the same documentation & costs as starting from scratch. Perhaps I would be just as well to take out another interest free mortgage on the new family home I intend to buy & leave the rental property mortgage free.