Everybody knows that San Francisco is build on a very steep hills and streets. I think that looking at a house from this perspective explains it much better than any mathematical equation can.
Take the scenic way and travel method... EV's (Electrical Vehicles) are very popular. even Segways
I would suggest to walk up Lombard street rather than down. Why, it is a nice walk up those stairs and once you get on the top, turn around and look at that beautiful view over San Fran