Want an extension at the back

[Partygirl2021]

I really want a single room extension at the back of my small terraced house. Nothing huge, even just 3x3 to give me an extra room. Problem is I have about seven outdoor steps from my back door to garden so not sure how this would work. My back garden slopes a bit too and has a garage at the bottom. I don’t mind losing garden space but wondered if anyone had experience of this? Steps inside or outside too?

My house had this done but long before I bought it. It has four steps running along the inner wall to the downstairs extension, with banister and handrail. This works because after a small space, it continues as a staircase to the upstairs. It does mean less space is taken out of the room.