hafez
I guess you're not familiar with London? Are you serious? With Terminal 5 the biggest contruction project in living memory you want to move somewhere else? That is sooo not gonna happen.
The third runway will be built between 27R / 09L and the motorways to the north. The area is not heavily urbanised believe me I've been through most of it. The big problem will of course be all the NIMBYs who will be on the new flightpath.