He's been wandering about the ceiling for a few days now and can jump. Likes to stay near the window but can explore the whole ceiling. Saw one exactly the same last summer, might be the same one. I don't mind spiders so he's quite safe.
Cheers beetroot. That is certainly the closest in appearance but the preferred habitat doesn't seem to fit. Can't find it today to get a better photo and there's no web visible unless it's outside the window and he just wanders in now and then.
I think the web will be very small, phoney. I'm no expert but I wouldn't take the description of the habitat too rigidly. I've seen them in places that are just a bit shaded, assuming they are the same spider, of course.
I saw a pair of wasp spiders in Deptford last year.