This all seems like a nightmare to me. Sorry to be frivolous but as Lime trees in England are prone to rot at the roots and fall over as they get older and top heavy, why not build the house and garage on wheels so you can re-locate the buildings into other positions either to suit your moods or, if the poxy tree has to come down in the future you could resume your original positioning without hassle. 
Don't you just love British planning laws? Next they will want you to re-position because there is something of archaeological interest near it, or maybe a rare species of rabbit has it's burrow where your lounge would be, or frogs cross the plot to get to water at mating time or...