I could be wrong, but I think I know what the reasoning is behind it. If you do something new, like pave the driveway, you're improving the house. When you've increased the value on your house, and claimed it on your taxes as a business expense, then you are no longer able to sell your house and keep the profit tax free. The taxes you'd pay on the house profits are way higher than any potential savings from claiming the reno.
Again, I could be wrong. I think an accountant friend of mine explained it that way, but it was s long time ago.