Ah, now I see the reason for the 'stairs' discussion. However I definitely think that the apartment has no stairs. This is why:
Look at this pic: http://static.guim.co.uk/sys-images...93788536274/The-Bristol-flat-of-Joann-007.jpg
The lawned garden is raised compared to the floor level of the apartment with a path leading in front of the basement windows.
To walk to JY's front door from the road you would walk down a slight slope http://images.mirror.co.uk/upl/m4/jan2011/9/7/jo-yeates-image-2-697085012.jpg
To me this looks as though upon conversion to an apartment, the ground has been dug down into, and the door has been dropped down in level to do away with the need for stairs - I can see an additional set of blocks at the bottom of the sandstone surround to the door, and the door has been dropped down a level so we now have a glass panel to fill the gap at the top. Check out the level of the bricks on the house wall at the ground level. Clearly the path is sloping.
quite different to the left side of the house where the ground remains flat to the main entrance then falls away into a steeper slope. jmo. Steepish slope is beyond the car in this image.
http://22.mm.g-media.com/666039.jpg
This is seen clearer in some pics than others. If you look at some pics of the height of the wall separating no.42 from no.44 you will see that it is high.
In other pics nearer the road it is not so high,indicating a slope. jmo. (Slopes do not always look like slopes on googlemaps or when using telephoto lenses) http://paimages.s3.amazonaws.com/categories/news/480x385/9984403.jpg
The apartment looks level to me - with a raised lawn - it's the path that slopes gradually from lawn level at the road gate to the door of the apartment.
in my opinion, the apartment has no stairs inside.
Edited to add: Apologies for those who have posted about the very same thing just now. I was preparing my post and missed the fact that many of you feel the same - no stairs.
I see what you're saying. It looks like the front of the building could have 3 feet more below ground than the back of the building. My guess then would be that there is maybe a small step inside the flat ... to give a little more head height. Does that make sense?