I did as suggested above, and built a gentle ramp up from the drive, around the side of the house to the back door. As there was then a 90 degree turn to get into the back door, I also had to add a flat wheelchair turning space right outside the door. The door also had to be Part M compliant, and the internal access route from it to the entrance level WC also had to comply with Part M.
Doing this allowed me to have stone steps up to the front door from the drive, which look a lot better than a ramp.
An alternative (not one I'd do, as I have a friend who's a wheelchair user) is to do as a friend in Yorkshire did with his self-build. He had York stone steps up to the main entrance, that were not Part M compliant. To get around this he covered them with polythene and then made a weak concrete mix ramp over the top. It looked pretty grim, but complied with building regs. As soon as the house had a completion certificate he just broke up the concrete ramp, revealing his unmarked stone steps...................