not back home there in Ontario but here on the lefty coast they build on every outcrop of rock they can find tho we usually put a little transition at each end , the guy who did my car has driveways up both sides of the house that are 100ft long and 12/12 or steeper ,I had to drive down the steeper of the 2 a couple of times with a fresh layer of snow and a creek across the street at the bottom Geronimooooooooooo