Dirt is your friend. Move Mother Earth, move the house up or down, or a combination to engineer a zero step entrance, the TO part of getting THROUGH the doorway.
Don't throw away useful dirt or rocks! Managing soil on a job site costs money so put every ounce to use. Think of those machines, like dozers and dump trucks, as taxi cabs with a meter. Whether digging, pushing or hauling, a running engine is operator time and ringing cash register. Dirt gets wasted on many projects, particularly when excavating basements, either spread around the lot or carted away. Think of that dirt (and rocks!) as your no-step ramp!