Ever regret loaning someone a book?
I'm trying to track down a novel I had in the early to mid 90's about a private detective in a large city divided into zones. Each zone had it's own quircky identity. In the zone he lived in the buildings were sentient and could change colour whenver they felt like it and you could only live there if they let you. His appartment changed colour each hour so he knew roughly what time it was when he woke up by the colour of the walls.
In one scene when he was being chased by the police the building he was standing beside created an abstract mural on it's wall which matched the colours of his clothes so he blended in with the wall and the police couldn't see him.
Towards the end of the book he went to a rarely used zone which was actually a run down seaside resort and met a friend with an aeroplane. The friend went up in the plane to look down at the sea and as the sea looked solid from the plane that meant the hero could walk across it to reach something he needed to get in the middle of the sea.
I think it was published sometime between '91 and '94 the author may have been British (I bought the book on the strength of a review it got in Interzone magazine) and I seem to remember it had a 2 word title.
I loaned it to someone not long after I read it and they moved away and the book went with them.