A walk-out is a house constructed on a slope

Thanks for that Sparteye. We have houses built on slopes too (and sloping houses come to that) but I don't think we have a word for them. My Aunt's house is built into the side of the Malvern Hills with the kitchen wall almost just plastered rock, and you can walk out of the upstairs bedroom to the garden (which is a 1 in 4 slope!).

And yes the floor at ground level is the ground floor in UK. The first floor above that is the first floor. We didn't think of naming the first floor you came to as the first floor

Rod