Up we go.
I'm under the impression that the subway tunnels are directly under Yonge, and I'd assume that most of those two-storey commercial buildings predate the subway's arrival in the area.My understanding with many of the buildings on the west side of Yonge, north of Sheppard, is that they lie directly on top of the tunnel boxes of the Yonge line, and so no foundations can be built on/around them. It's why, for example, that stretch of businesses along the west side of Yonge just north of Sheppard (where the Firkin is) can't be redeveloped despite everything else going on adjacent to it.