I found this spider with it's smaller mate it ting on a nest in my Yorkshire garage? I have never seen one of these before. The sack is about 8-10mm. I've managed to trap it under a regular sized tumbler in this picture.
It's a lace web/lace weaver, Amaurobius species, possibly A. ferox? Lace weavers are fairly common, I see more of the brown ones inside my home than any other spider (apart from perhaps Pholcus phalangiodes AKA daddy long legs spider).