“If you’re happy with the look outside and you want to be on the best street, then conceivably it’s a deal,” says Koffman. “Houses on the opposite side are trading at £3,500 to £4,000 per square foot. I can’t compare this house to those, but once this house is done, it’s going to be worth quite a lot of money, being Cavendish Avenue. Someone will trade off the aesthetic of the front of the house to be on the best road in St John’s Wood.”