[niwell]

Steely's pic looks more or less identical to the gap between our place and the semi-detached next to us! There isn't a specific name for it in Toronto as far as I know, even though it's the norm in most parts of the central city between semis and small rows. Just wide enough to fit a large garbage/recycling bin and a massive pain in the ass to keep clear during a heavy snow winter, or after an ice storm. Makes accessing the backyard much easier in summer though.

Alley's are referred to as "laneways" in Toronto, and a small percentage are named - mostly the ones that laneway housing facing them with a separate address.