Yesterday, February 28, 2025, the team installed the first piece of unitized curtain wall at One Delisle (on level two facing the outdoor amenity terrace and beside the indoor pool). Last year I was going around telling everyone that we would have glass up on the building in the first quarter of this year, and so I'm really glad that I was not made out to be a liar. Thanks team. This is a milestone date.

For those of you who maybe aren't familiar, there are two types of window systems that are commonly used in high-rise residential buildings. They are usually referred to as window wall and curtain wall. The former is more common in Toronto because it's, well, the cheapest; but there are curtain wall buildings other than One Delisle. Sometimes the same building might also use both systems. (In saying this, I'm specifically referring to the upper floors, because curtain wall is often used for ground-floor commercial spaces.)

The key difference is that window wall systems sit between floor slabs and get anchored at the sill and the head (the top of the slab on the bottom and the bottom of the slab on the top). Curtain wall systems, on the other hand, get anchored to the exterior slab edges and also "bypass" them. You can see that in the above photo. There are advantages and disadvantages to both systems, but generally speaking, curtain wall is viewed as higher quality, and the more expensive option.

In the case of One Delisle, we explored and were open to both options during the design process. But ultimately window wall just didn't seem like the right system to realize the unique geometries of this building. So we went with curtain wall, worked through a lengthy design-assist process with the subcontractor, built a bunch of mockups to make sure everything looked and worked well, and now it's being installed on site.

Level two is likely going to be the most challenging floor because of the double-height pool area. So I'll be sure to share more photos once it's all enclosed.