The living roof takes root in Maine.
By Sara Anne Donnelly & Virginia M. Wright
Photographs by Trent Bell
Many a Mainer will insist his or her local Hannaford is special or unique, but when store #20888 opened in July 2009, shoppers on Augusta’s east side genuinely had a Hanny to crow about: the world’s first platinum-LEED-certified supermarket. The store made headlines for a number of green initiatives — geothermal wells, hyper-efficient refrigeration — but to look at it from the parking lot, the main thing a shopper notices is the unusual tiered roof, which hosts 7,000 square feet of sedums, making it Maine’s largest “green roof.”
Compared to more urban and heavily developed parts of New England, vegetated-roof construction has been slower to catch on in Maine, where access to green space and stormwater management are less pressing issues. But some architects say the state may finally be catching up on a trend that, according to one industry association, has nationally seen double-digit growth year-over-year for most of the last decade.
In the 10 years since it was sown, the Augusta Hannaford roof has been proven to reduce heating and cooling costs, and the sedums have thrived despite Maine’s weather extremes, spokesperson Ericka Dodge says. Building a living roof involves topping a flat or sloped surface with layers of customized dirt, drainage, and waterproof membranes that are collectively known in the biz as “plant media.” Hannaford’s sedums are planted in 1-by-1-foot modules, making them easy to replace if they die, but that’s seldom been necessary, Dodge says. In fact, they’ve required almost no maintenance at all.
Since the surface of any roof is a relatively shallow and unforgiving zone, exposed as it is to sun and weather, sedums, which store water in their leaves and have a metabolism that minimizes moisture loss, tend to be the green-roofers’ go-to. Other options include blueberry bushes, rugged grasses, and even vegetables. In the best cases, a green roof is a low-maintenance, eco-friendly way to mitigate stormwater runoff, extend a roof’s longevity, and insulate a house from summer swelter.
That’s proven true at Luminato, a year-old condominium complex in Portland’s East End, where residents gather on a rooftop deck surrounded by a sedum lawn that turned gold in fall and remained colorful through the winter. “We had no winter kill, and it doesn’t require much water or care — just a little bit of weeding,” says Erin Cooperrider, an architect with Luminato’s developer, NewHeight Group.
Now, the company is putting the finishing touches on a living roof at nearby Verdante at Lincoln Park, the very name of which implies some of the roof’s less tangible benefits. Besides moderating temperatures in the building and reducing storm-water runoff, Cooperrider says, “It’s also very lovely. It’s a thing of beauty.”
Both NewHeight and Hannaford regularly field requests for green-roof tours from architects, contractors, and construction-technology students. “I expect we’ll be seeing more green roofs being built in the near future,” Cooperrider says.
But lest you rush out with a ladder, a bag of soil, and a dream, know that executing a green roof means working with an architect and contractors experienced in this kind of work. “People should really do their research,” says Tamara Stock, whose passive and active solar house on Pemaquid Pond has a sedum roof. Since Stock’s house was completed in 2010, her green roof has had problems, including an infestation of bright-pink weeds and a sedum die-off after a drought. To rescue the plants, Stock and her husband attached an oscillating sprinkler to a second-floor spigot. Though she has no regrets, Stock says, “It needs maintenance. It’s not a free thing.”
For Carol Morris, a green roof was an important way to mitigate her eco-guilt about building a new house in Kennebunkport, so she hired Portland architect Will Winkelman, one of Maine’s more experienced architects in green-roof design. “It was just an emotional thing for me,” she says. “It would be sort of a symbol of a house that would put as little footprint on the land as possible.”
Today, her second-floor office window looks out on a 250-square-foot miniature meadow of fescue grass growing 12 feet above the ground. It looks like this land along the Little River, fringed with oak and maple and birch, is already reclaiming Morris’s barely four-year-old home, or, even more unbelievably, like the home, all shiny silver-metal roofing and tidy gray cedar clapboard, has somehow always been there and is only now shaking off the earth to venture out.
On a recent morning, Morris swiveled in her office chair to see a bright-red cardinal and two orange-breasted robins poking around the long grass on her roof. Four years ago, it was Morris who crawled out on the dark soil to sprinkle it with fescue seeds. And she’s been the one tending to it ever since. But now, she says, “I may end up letting the roof do its own thing as opposed to having it look more elegant.” The roof seems ready, Morris thinks, to grow wild.