While shooting the site today, I noticed it was at grade for 3/4 of it and this tower is going to be Structural Steel framing. Since this is a climbing core by itself and can see anchors in the concrete deck, it has to be a steel building. It's odd seeing steel framing when most are concrete these day like 16 York St, One York and so on. The 2 BA towers were steel, with some steel in the EY building. Even 88 Atlanta 5 story building is steel framing.
Its very possible it could be concrete with a transfer floor like 488 University. Time will tell, but moving very fast.It's clear that the lobby/podium is going to be structural steel (the anchor plates for the columns are visible), but is it not still possible that they throw down a transfer slab and switch to reinforced concrete for the tower section? We've seen that kind of construction before in Toronto (one example is the condo at Dundas/University, and I believe the new Four Season also has concrete over a steel podium in some areas).
It makes a lot of sense for the lower levels to be steel (especially with the bridge connection for the park, and the high overhead clearances for the bus bays), and I'd like to see more steel go up in Toronto, but I could've sworn someone told me this was going to be another concrete tower.