This spider, body length approx 20mm - I didn't get closer as it was acting rather defensively/aggressively - ran up my curtains last night. I have not seen anything like it before. With it's furry grey abdomen, I thought at first it was a Mouse Spider, but seems too big. I then thought maybe a colour variant of Tegenaria spp but the abdomen is really quite plump compared to photos I can find. Interestingly, in the photos its patterns are showing up - wihtout the flash, it just looks very grey. it has spun itself a flat web with a hole in the middle that it was sitting over.