Good to see someone is looking into this. I live in a tenement on London Rd on the second floor. The people on the third floor have claimed the area at the bottom of the stairs as their own so there is no other space in the stairwell.
I keep my bike in the hallway of my flat. It does get a little but frustrating. taking the rubbish out, cleaning up, entering and leaving the flat when 'somewhat impaired" - you get the idea.
I've recently found out that one of my flatmates has recently bought a bicycle and keeps it in his bedroom. The situation is not good for anyone!
Does it impact my cycling? Sure it does. Daily commuting is not too bad, but at the weekends it can be pretty bad. It is really annoying having to carry the bike up to the flat when I'm only quickly dashing into the appartement then back out 5 or 10 minutes later.
As for cleaning the bike - All I've got is the bathroom. I've had some worrying looks from the flatmates as I emerge all hot at steamy after an hour in the bathroom with my bicycle. I swear I was only cleaning it...