Apparently I've been living in the dark ages. The One Delisle project team just introduced me to Bluebeam Revu and, frankly, I'm not sure how we were marking up PDF drawings before this. It's faster and more responsive than Adobe Acrobat. Everyone's comments sit nicely in the cloud. And you can even take measurements off of the drawings. It kind of feels like a light and friendlier version of AutoCAD (which I haven't used in over a decade). Marking up drawings is something that I do regularly as part my job. Sometimes I do that with trace paper (I did that for probably every suite at Junction House). But more often it has been with Adobe Acrobat. If you're in the same boat and aren't yet using Bluebeam, I would encourage you to check it out.

Alex Bozikovic (architecture critic for the Globe and Mail) is one of the most vocal proponents of more housing and more density within Toronto's low-rise neighborhoods. Last year, he organized an international design competition where he asked firms to come up with innovative, yet sensible, solutions for how this could be done. I'm a little late getting to this, but today I'd like to walk you through this immensely clever solution by Batay-Csorba Architects, called Triplex Duplex.

The project uses two prototypical, but random, semi-detached lots from the Christie & Bloor area of the city. Each one is 18' wide x 100' deep. So your typical long and narrow lots. From the street (see above image), it looks highly contextual. But in plan, you begin to see the 3 main volumes of the project emerge. Here's a ground floor plan from the architect:

Each volume is around 2,500 square feet. I presume that includes the basement. If you exclude the basement area and the vertical voids throughout the project, which you're allowed to do in your calculation of gross floor area in residential zones, I suspect we'd arrive at an FSI (density) number that isn't that much more than what already exist in these sorts of areas.

At the front of the house (right side of the above plan) is a set of stairs (and a patio) leading down to the front basement unit and a set of stairs leading up to the main front unit. An inset patio also forms part of this main entrance (image below), which is a great way of adding outdoor space while at the same time maintaining privacy across the units. These strategy is one of my favorite aspects of the project.

The rear units are similarly accessed at the back of the building. And the two middle units are accessed along the side of the house. All in all, this housing typology has the ability to accommodate up to 6 units: 3 main suites and 3 secondary type suites. By the architect's own estimate, this could result in 147,000 new housing units across the city if every lot occupied by a semi-detached house were to be redeveloped in this way.

But I wonder if any consideration was given to the secondary (basement) suites that may already exist in these zones. Because in some cases, and as beautiful as these homes may be, we may only be talking about 2 additional suites. Triplexes are also already allowed in some areas of the city. So does this ultimately achieve its intended goal, which is the creation of more "missing middle" housing in order to ease overall housing pressures? Or do we need to be thinking bigger?

As a follow-up to this post (subscribe to stay connected), I am going to look at what a development pro forma might look like for a project of this scale. The numbers have a way of answering a lot of questions. That said, kudos to Alex for taking on this initiative and kudos to the design team for a pretty spectacular architectural solution.

All renderings by the talented Norm Li.

Over the weekend I stumbled upon this illustrated Medium post by Alfred Twu comparing sloped and flat roofs. The argument is that these two roof types are coded. In this part of the world, at least, sloped roofs signal low-rise "house" and flat roofs signal big city "high-rise."

I'm not yet convinced of this association with height, or of all the claims made in the article. Did New York City really make the flat roof commonplace in our cities? But the idea that a roofline can trigger certain associations -- or even become divisive -- is a fascinating one.

Take, for example, Am Fischtal in Berlin. On one side of the street you have, still to this day, homes with flat roofs. And on the other side you have homes with sloped roofs. This clean divide is the result of a supposed "roof war" that took place during the Weimar Republic.

At this moment in time in the suburbs of Berlin, the kind of roof you chose to live under was a proclamation of your political orientation. I'm not sure roofs have as much gravitas as they did in the 1920's on Am Fischtal, but they still do say something.

Image: Alfred Twu