This is one of the Lace Web spiders, Amaurobius sp ., and probably Amaurobius similis.
Several species of lace web spiders are common around the outside of our homes and gardens. They make a characteristic lace-like web on fences, sheds, walls and among general clutter around the garden.
Males are prone to wander indoors when mature and looking for a mate. Bites have been reported when a spider has been trapped against the skin, but with little pain or lasting symptoms.