It's a sloppy build. Not because they left out a door or by design no door (teleportation needs stairs but no door?) but because of where they set the stairs. There is a one tile space between the staircase and the wall and then a rail that seems odd there. I would have put the stairs connected to the back wall and moved the inside wall if I wanted a door. The one tile space (outside) bugs me more than the missing door. A good contractor would have went back to the architect and ask them what are you thinking? (Because of the one tile space) then tried to block it with an object so Sims don't go behind those stairs...and in older games they would have been out there stuck between the staircase and wall. Sloppy. ETA: It bugs me as much as when I see lots with windows not centered and all over the place and anyone who studies a house long enough will start to see how inline architecture is, windows aren't on the edge of a building (rarely) it would hurt the foundation. And a window isn't normally out of sync with another window in a room, again it would hurt a foundation wall, and or weaken a wall.
