Tommy meets Quantity Surveyor, David Holmes, and his wife, Annie, who want to turn their derelict garage into a therapy and sun room. Annie has never seen a saw before, let alone used one, while David has relied heavily on builders in the past. So Tommy's got his work cut out persuading them to get their hands dirty to save money. From replacing the old roof and cutting in the new rafters to tackling underfloor heating - can they rise to the challenge and come in on budget?