At first glance, green roofs seem to offer one of the most thorough and aesthetically pleasing marriages of green building form and content in the entire pantheon of green building techniques. Dorks like me will always love our insulation, and trendoid LEED Brain spendaholics will brag on their rooftop wind turbine, but green roofs manage to bridge that gap by offering a host of sustainability benefits while also looking pretty spectacular. The biggest green roof in New York City, for instance — or at least the biggest green roof that doesn’t aspire to being a farm — is this one, atop the Morgan Mail Processing Facility on 28th Street, which Preston Koerner profiled at Jetson Green. Click the link and you’ll see something that looks more like a lovelier-than-average park than it does like a grassy roof, and which is about as awesome a workplace perk as I can imagine. (At least until they invent a coffee machine that also dispenses scotch and flattery, which I assume is in the works and hope gets Energy Star certification) But considering that green roofs are probably the most beautiful non-architectural manifestation of green building that we’ve yet seen, and that New York City has worked hard to incentivize green roof construction with a property tax credit of up to $100,000, it’s both baffling and kind of sad that green roofs just aren’t catching on in New York City.
“In New York City — where lawmakers and environmentalists had hoped the state green-roof law would make a major difference — the most popular vegetated roofs are atop schools and government buildings,” Nathanial Gronewold writes at E&E News. “While no one can say for sure how many green roofs can be found in the city, all agree the number is puny. And while new building design and energy conservation standards are quickly spreading here, there seems to be no fervor for green roofs. What is catching on is a cheaper, less glamorous solution: whitewash coating the heat-absorbing tar to deflect the sun’s energy away from the building.”
It’s not surprising to hear all this, really. For one thing, whitewashing roofs is a really excellent idea and a very simple way to make a roof more efficient. It, too, has been incentivized pretty aggressively by Mayor Bloomberg and Con Edison, among others; there was a gbNYC post on this from a few months back that has not yet made it to the new, WordPress site. Furthermore, where green roofs are expensive and ambitious and (most importantly, structurally speaking) very heavy, a whitewashed roof delivers energy savings for the cost of one hard day’s work plus paint. It’s easy to do the cost-benefit analysis, here — the back of an envelope (while we’re breaking out the biz-speak cliches) isn’t even necessary. And yet what gets left out of that equation — what is inevitably left out of cost-benefit analyses, given that it’s unquantifiable — is the aesthetic grace and basic goodness of a green space on a rooftop. Green roofs offer much more of those harder-to-quantify benefits than do white ones — the Morgan Mail Processing Facility’s green roof is a show-stopper, but it has also helped cool the building, saved $2,000 a month in costs related to storm water runoffs, and doubled the roof’s life expectancy — but they also cost notably more. The Morgan Mail Processing Facility’s roof cost nearly $5 million to install. It’s still unclear just what kind of energy savings are conferred by a green roof, but going by the anecdotal example Gronewold cites of Con Ed’s green-roofed Long Island City facility, it’s considerable — Con Ed is claiming an 84 percent reduction in summer heat. Con Ed also claims a 67 percent reduction on white roofs. You see, probably, where this is heading.
I spend a lot of time here waiting and hoping and looking for signs of the market shifts that will — and I believe they will — eventually make green building and green retrofits and suchlike real and really profitable concerns. Already, green building costs are nearly equal to conventional methods, and it seems that we’re not far from the institutionalization of a more progressive approach to building both thanks to state action and the more compelling demands of the market. That’s a good sign, and a good thing. But in the case of green roofs, we may actually be seeing the incentives running in the direction we’re all more used to — away from the transcendent, that is, and back towards the mundane. Saving energy is a good idea, and people are going to want to do it — I believe that, and I believe that wish will become more widespread as the end-user costs of energy come more into line with its true cost. The problem for green roofs, though, is that while they may offer more energy savings than whitewashed roofs, they cost enough more that they’ll probably (and, I suppose, reasonably) be consigned to fringe-y status — something for rich people and ambitious municipal projects. Something, in short, of a “have you seen my lovely wind turbine?” showcase. The market could shift, of course, and change that. And green roofs will exist as long as people want to make the places in which they live and work both more beautiful and more efficient; in other words, forever. But if the market doesn’t catch up, then green roofs aren’t going to catch on. It’s going to make perfect sense, and it’s going to be a pity.