Mute* via Flickr There was a joke, I hear, told in Toronto in the 1980s, when the city’s first condo boom was throwing up buildings like the Polo towers and 1001 Bay. “They call them condom-iniums,” it went, “because the developer gets to screw the buyer without incurring any risk.” I know this not because I was moving in ribald real estate circles back then, but because it’s the epigraph to a short paper written by Ted Kesik, an engineer and a University of Toronto professor of building science, on the subject of glass towers. “Virtually all of the glass condominium towers feature window wall systems that enclose the entire facade of these buildings,” he writes. “Window walls are thermally inefficient compared to curtain walls or punched windows, and they also exhibit questionable performance in terms of durability, air and water leakage. Industry experts forecast that many of these window wall systems will require extensive retrofit or replacement within 15 to 20 years”. What does this mean to the buyer of the window-wall condo? According to Kesik, “Inferior quality building envelopes and deferred maintenance will eventually deflate the prices of resale condo units. A generation of new condo buyers that is planning to build equity and eventually move up to single-family detached housing as they form families will be stranded with devalued assets. And so will the empty-nesters who cannot sell their homes and get on with retirement.” Kesik’s paper is used as part of a CBC series called “When Glass Towers Attack!” or something similar. The summary text, posted on Nov. 14, is a questionable piece of journalism. For instance, it brings up the cost of retrofitting First Canadian Place, which is not residential, and is not getting its window-wall replaced, for no reason other than to use its shocking price tag – $130 million – to get condo buyers worried about what they’re on the hook for. It also doesn’t seem to know the difference between a window-wall and a curtainwall (about which, more later). The more in-depth series linked to in this piece is little better, and goes so far as to undercut a quote by describing one interviewee’s positive comment about glass in commercial towers as being the result of his “carefully choosing his words, so as not to be too harsh about Toronto’s wall of glass.” And that “hook” that condo buyers were on for scary amounts like $130 million, when discussed in more detail, turns out to be mostly taken care of by the reserve fund, money taken out of the usual condo fees and set aside by the condo board for future potential expenses, like window repairs. Kesik’s paper is a little less unhinged, though one thing that struck me even there was the fact that, though he’s a professor of building science and therefore presumably something of an expect on the subject, Kesik cites “industry experts” in his estimation of the lifespan of an average window wall. An educated opinion piece, then, rather than an expert declaration. Which is fine – better an educated opinion than an uneducated one, so let’s focus a little on that. It is pretty incendiary stuff nonetheless, given how many of these glass towers are being built, and how much money developers and buyers are putting into them. And the CBC has run big enough with opinions like this to bring the very concept of the window-walled condo tower into question. So I figured I’d find a couple of those industry experts myself and try to figure out if, despite the CBC’s poor handling of the subject, we actually are all screwed. The CBC series quotes Doug Webber, the Canadian green building practice leader for Halsall, an engineering firm that specializes in both cladding engineering and energy consultation. Despite he and colleague Sally Thompson being depicted as anti-windowall, Webber disagrees with all the series’ major points: he doesn’t think glass condos are especially energy inefficient, that they’ll end up costing condo buyers anything outside their regular condo fees, or that entire sides of window-wall buildings will have to be replaced all at once. “If you actually look at a typical interior unit,” Webber says, “even if it’s a 100 per cent glass [building], it’s actually only 25 per cent of that walls that are glass, and most houses would have about 20 per cent, but just spread over four walls.” You do lose energy through windows, he says, but it accounts for only about 20 per cent of a condo’s energy use, roughly the same amount as heating and cooling the outside air for ventilation, or lighting the place, or using your appliances. He says the biggest issue is size. An average house is slightly more efficient than an average condo – Webber says condos use about 25-30 kilowatt hours per square foot, houses about 20-25 – but houses, having on average far more square feet, use more energy overall. I asked him about what he thought of the CBC series, which was published as well as broadcast on the radio. “One of the things I think was misrepresented was the focus on the cladding, the focus on the glass. It is one piece of where the energy goes, and sometimes we over-think how much energy goes through the envelope…If anything,” he says of the series, “there was too much alarm in it.” Peter Clewes is an architect with Architects Alliance. He was not quoted in the CBC series, but has a few opinions about its findings and implications. Clewes is as close to a king of the glass tower as we’ve got in Toronto. He’s been designing them for about 25 years, and is the man behind the new Four Seasons, the Thompson Hotel, Spire, Casa and York University’s Pond Road Residence, the first hyper-green student housing in Canada. He’s generally rather well thought of. Christopher Hume, for instance, has called him “the leading condo designer of his generation.” First, a definition of “window wall”, which according to Clewes is the “most misunderstood word in building lexicon. Whether it runs floor to floor, or whether it runs brick opening to brick opening, it’s the same system. Polo, for example, where it has some brick, people stared to think it would be kind of nice to take the window right down to the floor. It was used to differentiate between that system, which is supported on the slab, versus curtain wall, which hung outside the building and goes past the slab. It’s a terminology to distinguish between those two systems. Virtually every high rise in commercial Toronto is a curtain wall, it’s hung outside the building on clips.” I called him up recently and presented him with the case, Kesik’s and others’, that we should be concerned with how our skyline is filling out. It turns out that he disagrees with Kesik & Co. You could make the argument that he has a conflict on this issue; he makes his living from building the very buildings people are worried about. You could also argue that he’s been doing this all his life, is at the top of his field in Canada, and maybe wouldn’t be making buildings he figured might not work. Read on and decide for yourself. “Sealed units – that is, making double-glazed units within a window frame – has been around about 50 years,” Clewes says. “What we know about them is that on average, they will fail within 35 years. ‘Fail’ means you will get some fogging in some windows in some parts of the buildings.” Some fogging in some windows. That sounds a little less dire. But Kesik says, and the CBC quotes and implies, that when those window walls start to fail, the entire building will need to be re-sealed or re-clad, resulting in enormous special assessments for condo owners already dogged by maintenance fees. Clewes disagrees again. “It would not be re-cladding,” he says, “it would be unit by unit. Even in the theoretical life span of 35 years, you will get the odd unit failing, and you replace them incrementally.” 35 years is a lot longer than 15 or 20. “To say buildings are going to fail in 15 years is kind of absurd,” Clewes says when I mention Kesik’s and the CBC’s estimates. Clewes points out that window walls are not the only things that need maintenance after that kind of a span of time. Roofing and mechanical equipment like elevators do, too. It’s entropy and it’s inevitable, but according to Clewes, window walls are no more subject to it than most other things. “If they’re built properly,” he says, “there should be 30 years before you need to do more work.” But there’s the rub: If they’re built properly. “I think we are going to see some failures because there are some really poor quality window wall systems that are still being used,” Steve Gusterson, a manager at Alumicor, a Canadian company that manufactures curtainwalls, told the Daily Construction News recently, “but I wouldn’t want to paint the entire market segment with that brush. It would sound like sour grapes from a guy in the curtainwall business.” In the same story in DCN – a publication of the building trades – Darius Rybak, vice president of Aspen Ridge Homes, which recently decided to affix a curtainwall to their high-end 16-storey condo at 77 Charles Street, says their decision was largely aesthetic, and that he and his company figure window walls don’t present any particular problem unless, once again, they’re poorly installed. “Could window wall systems be better?” Clewes asks. “Absolutely. We are in a very highly competitive market in Toronto. What’s remarkable about the housing market in Toronto is that it is relatively affordable, there is virtually no other city in North America that can deliver housing at the price point we can in Toronto. “As an architect, I would like a higher-quality cladding system. Why? Because I think it looks better,” he says. “These systems could also perform better thermally. But in a competitive market, it’s very difficult to get people to say they’ll put a higher quality material and charge the same price, they’ll charge a higher price, and they won’t sell as well as other projects.” I ask him whether he’d ever heard of a condo building having its entire window wall fixed or replaced all at once. “I’ve never, ever heard of that being done,” he says. He’s convinced that, though the government regulations covering energy savings could use a lot of improvement – “I think Canada has one of the weakest energy codes anywhere in the Western world” – the ones governing construction quality are behaving as they should. And though the green codes could be better, Clewes has one more thing to disagree with Kesik on. “If you take a tower, it’s probably 70 per cent more efficient than a house,” he says, “because it has heat loss in only one exterior wall; the other three walls are adjoining other units or the hall. And it has no roof.” There are any number of reasons not to buy a condo: maintenance fees; belligerent condo boards; a lack of reserve fund studies on buildings built before 2001. But as far as Clewes is concerned, you shouldn’t really be worrying about the glass. Though you probably still should be using condoms.
