They want to ensure they will get their money back, and that if a borrower defaults on the mortgage, [they] will be able to sell the property and recoup their losses that way.

For a listed building or something very unusual, you might need a specialist survey carried out by somebody who really understands that type of property. And some very unusual buildings are in a poor state of repair. So lenders might release the money in stages, and get someone to check before they release any more.

It costs a lot of money and effort to do this. Most people would opt for a bridging loan.

When a mortgage deal has a low rate and high fee, generally speaking, it best suits a borrower with a fairly sizeable loan. On these 3.99 per cent deals, the fees mean they best suit those borrowing £175,000 or more.

Such a limited selection of providers means interest rates tend to be at a premium to standard home loans - although [arrangement and valuation] fees are comparable.

It's rather good value when you consider that, two weeks ago, the best five-year fix was 4.69 per cent from the Portman building society. The [Woolwich deal] has no extended redemption penalties, is available up to 95 per cent loan to value, and the arrangement fee is average.