It really seems to like our garage and is the bane of my girlfriend (as evidenced by all the screaming when on two occasions one got into our home somehow). I was never able to spot this kind outdoors, which is rather odd (there are plenty of Araneus diadematus spiders in the area which are fairly easy to spot).
It's hard to tell on the photo, but these spiders seem rather big (at least as far as spiders in Poland I was able to spot go)... somewhere around 5cm at least (legs included)? They really do make for rather large, black spots against an otherwise white garage wall.
I'd really like to find what kind of species this is so that I can, hopefully, convince my GF that it's harmless to humans. Unless it isn't, in which case I'll start getting scared of walking into our garage. ;)
PS. We live in Poland, Poznań.