I will admit I was looking more towards to the south-east of the airport ... where there appears [on Google Earth] to be a rather tiresome river and a lot of industrial buildings.
However, my point is more general: I say again ... how far does one go? and at what cost?
@ Forget ... I take your point. An "interesting" activity. However, well outside the safeguarding areas. Change [extend] the parameters and, world-wide, you would be bulldozing whole swathes of cities, motorways and other infrastructure [and filling in those lovely useful reservoirs west of LHR].