Julian Bowron, designer of the Metaloq steel framing system, used a term I had not heard since 2015: "tolerance accumulation." It's likely one of the construction issues at 461 Dean, the problematic prefab modular tower in Brooklyn that Treehugger followed closely. It is what happens when you have a little construction tolerance allowance and you let it pile up, adding it to the tolerance allowance on the floor below; eventually, things just don't fit.

Bowron has been in the business for a long time and has seen it all. Now, with partner Blair Davies, he has developed the VECTORMinima Metaloq system to address tolerance accumulation and many of the other problems with modular construction. He tells Treehugger: "Six thousandths of an inch, that's what this is designed for. Go up ten stories and the tolerance is no thicker than a business card." The first structure, shown above, was assembled in Toronto in October.

The important feature here is that they are supplying all the components needed to build a really strong, square, steel box, and have resolved all the connections to hold them together. As described by the company:

To understand why this is so significant, compare it to how it has been done in the past. Seven years ago in Brooklyn, I watched as a box made from heavy steel (photo above) was being welded together by workers in a manner no more sophisticated than if they were doing it on site. (I have also been involved with prefab and modular for many years, and follow it closely.) There is no real system to it at all, just a box that gets stacked.

With Metaloq, it is all about the corners and their connectors, much like a shipping container. Unlike a container, those corner fittings are part of the cold-formed steel frame, one piece from top to bottom for greater accuracy; you just drop it down onto the vertical connector.

Metaloq with Millie's cookie

It becomes a magic box because of the connectors at the corners, the vertical one that acts also as the hoisting point, and the horizontal one that I describe as a dog cookie because of its shape; Bowron laughed and suggested that they might just start calling it that.

The cookie has tapered sides, so as the ironworker screws in the bolts, it pulls the boxes together into exactly the right position.

Then you just drop another box on top, stick a bolt through that vertical pin and you have a tight, perfectly aligned fit, literally in minutes; in fact, "18 minutes from truck to set."

There is a lot of other stuff going on, like how the lightweight floor joists are connected to the frame, all designed for speed and accuracy.

The structure is ridiculously light, starting at 12.5 pounds per square foot ("I'm not kidding!" says Bowron) and can go to 10 stories with the current design; beefed up a bit, it can go double that.

There are many things to unpack here. Treehugger isn't usually a fan of steel construction given the carbon footprint of making steel, but this is all made from recycled steel out of electric mini-mills, and more importantly, isn't using very much of it at 15 pounds per square foot of floor area. We have always promoted wood construction, but as Paula Melton of BuildingGreen has noted, it is not a get-out-of-carbon-jail-free card. "Consider which materials and systems make the most sense for the project, and optimize how you use them," she says. This system is seriously optimized.

It also creates some really interesting opportunities. One of the biggest problems in modular construction is the cost of shipping big boxes of air, and going from state to state with each having its own rules for regulating modular construction. With Metaloq, you can squeeze a pile of them into a shipping container and send them to a warehouse or empty factory or even a tent near the site; all you need is a flat floor and a wrench to put them together. That's why the business model is to sell them to modular builders who can finish the boxes; they are just selling the frames. And at under thirty bucks a square foot, it's a really economical system.

Julian Bowron isn't stopping there; he has big plans for integrating mechanical, electrical, and plumbing (MEP) connections right into the units. I thought this wasn't a good idea, claiming that almost all problems happen at connections, and here he was, significantly increasing the number of them. He dismissed the argument, noting "I have dozens of hose and electrical connections all around my factory carrying way higher pressures than any plumbing connection and they don't fail."

And wait, there's more; once the modules are powered through those connections as soon as they are dropped, critical systems can turn on and actuators can place the pins into the connections. I thought this was a bit much too, but Bowron responds that "Actuators cost thirty bucks. Ironworkers cost $120 per hour. This pays for itself almost instantly."

Having figured out how to build a module that goes live autonomously, Bowron then wants to assemble it robotically with his concept for a "drone halo." Again, I thought this was pie in the sky, noting that they don't even have this on container ships. He corrected me again, explaining how they unload a ship with 25,000 TEU (Twenty-foot Equivalent Units) of containers so quickly, with robotic cranes that can adjust for angle and tilt, picking them up and dropping them on robotic trailers. There is nothing that he is proposing that is not already being done with containers; the only real difference is that the Metaloq box is bigger.

Although I was invited, I didn't attend the set of the first little building made with Metaloq, because of COVID-19 concerns. I really regret that now; it's not on the level of missing a moon launch, but it will likely be considered a significant event in the history of modular construction, which I have been following for fifty years. This isn't just building boxes in a factory but is true system thinking, and it is going to be a very big deal.

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