(Parasteatoda tepidariorum)
The American House Spider is a fairly common arachnid that is likely to escape notice, as it tends to build its web in out-of-the-way places. Although they are called house spiders, most of the ones I’ve seen are outside, in our sheds, or the greenhouse. Their web behaviours are efficient, with little wasted motion, and as such, they easily go unnoticed.
There are several species of this genus on the Island, but all of their colorations are in shades of brown, making them hard to tell apart. They are also rather dull, making it easier to blend into the background.

They don’t bite people with any regularity, and their venom is not dangerous to humans. Their bodies are generally around 1 cm long. Many species of American house spiders share a body shape & size similar to that of female widow spiders. Black widow spiders, though, are glossy black, with a characteristic, red hourglass marking on their undersides.
Thank you for your post. This has been clarifying.