Here's an interesting question. It's often said that ground source heat pumps are better than air source heat pumps but the problem is that you have to dig up a lot of your garden to fit the pipe work. If you were having a new driveway, would that give you sufficient area to install the pipe work for a ground source heat pump or would it need more space than that (though I realise that depends how big your drive is!)
If this could work, what would be involved? Do you just bury the pipe in the soil and then lay your drive tarmac/concrete/block paving as normal? Would the weight of the car be a problem or is the coil buried sufficiently deep that this would not be a problem.
I remember a couple of winters ago, someone posting here that they wanted to do this in reverse and lay a coil under their drive to melt snow. Presumably this would require a completely different approach because I imagine you would need to insulate under the coil to make sure the heat went up into the drive, not down into the ground, but the coil would have to be close to the surface to make it effective but the coil and insulation would have to be able to withstand the weight of the car.
I seem to remember the person who asked about this being told off for global warming but he said it was to stop his wife slipping on the ice and breaking an arm. Just to reassure any critics, these are all hypothetical questions this time!