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Environment and Outdoors

'Going Passive' - And Slashing Energy Bills by 90 Percent

Trent Bell

CUMBERLAND, Maine - Four years ago, Maine saw the construction of its first so-called "passive house" - a building designed with efficiency standards that can cut energy bills by up to 90 percent. Since then, the trend has been growing exponentially. And Maine builders are helping to lead the way.

On a four-acre site just off Route 1 in Cumberland, the foundation is being laid for the new home of the Friends School of Portland - a Quaker day school for pre-k through eighth grade. If all goes according to plan, this 15,000-square-foot property will be the biggest building in the state to meet passive house standards, and only the third school in the U.S. to do so.

Architect Phil Kaplan says it should also qualify as a "net zero" building, meaning it puts at least as much power back into the grid as it takes out. And he says buildings like this need to become the new normal.

Credit Trent Bell
Passive design is employed in this GO Logic building at Unity College in Unity.

"And it absolutely has to happen if we're going to do what we need to do to save this planet," Kaplan says. "Things are going to have to change."

Kaplan says that must ultimately be driven by the introduction of new building codes. For now, though, "going passive" is an increasingly popular option in the construction industry.

Passive design standards were first developed in Germany in the 1990s, and there are some 30,000 passive house-type buildings worldwide, mostly in Europe. Here in the states, there are about 130 passive house structures - either completed or under construction.

The Friends School project in Cumberland will incorporate solar panels, but more critical to passive design, says Kaplan, it will also make full use of natural light. "Passive house construction typically uses a different kind of window - in this case we're using triple glazed windows," he says.

Probably the most important factor, though, is insulation - a lot of it, everywhere. "We're adding more rigid foam to the exterior of the typical shell - another 4 inches beyond what typically is seen in this type of construction," Kaplan says, "and we're adding a lot more insulation under the slab and to the roof."

With all this extra insulation, of course, Kaplan says ventilation is crucial. "Built tight, ventilate right - we always have mechanical ventilation in all of our buildings now," he says.

Credit Tom Porter / MPBN
Jenny Rowe, of the Friends School in Cumberland, at the site of the school's new passive designed building under construction.

"We're really looking forward to being in a new place," says Jenny Rowe, the head of the Friends School of Portland, which has almost completed the project's $2.5 million fund-raising goal. After this building is complete, a second phase is planned - including a gymnasium.

Rowe wants to use the new campus as an educational tool, enabling students to learn first-hand about environmentally sustainable living. "We'll have a dashboard for students to be looking at to see how much energy we're generating from the PV panels, and they'll be able explain to people who come to visit how the building works," Rowe says.

The school is not the only large-scale passive house project in Maine. Naomi Beal, director of the advocacy group PassivehausMAINE, says a couple of multi-unit residential buildings are now in the planning stages. "We're really looking for those bigger buildings," she says. "It's easier to achieve passive house standards with a bigger building."

Credit Trent Bell
The interior of a GO Logic passive designed home in Belfast.

She says that's because the buildings' larger interiors make them easier to ventilate. Moreover, Beal says the conversion to passive standards would not be that costly. "All of the major buildings that are going up, all of the multi-units that going up, could be easily built to passive house standard without a tremendous amount of extra expense," she says.

For example, the construction costs of the Friends School here in Cumberland are on track to be only about 3 percent above the average. Alan Gibson says that's not bad when you consider we're talking about the most stringent building standard in the world. Gibson is co-founder of G-O Logic in Belfast - the architecture firm that built Maine's first passive house dwelling more than four years ago. Since then, the company's growth has been explosive.

Credit Trent Bell
GO Logic passive house design at the Warren Woods Ecology Field Station at the University of Chicago.

"Well, in 2010 when we completed that building, we had four employees, and now we have 22 employees four years later," Gibson says, "so we've seen a lot of growth. From that one building we now have 50 residential units that we've completed and a couple of institutional buildings."

Those achievements include a 36-unit co-housing and eco-village in Belfast, as well an ecology field station for the University of Chicago, which he describes as the first passive house-certified laboratory in North America.

Gibson says he's upbeat about the future, as more and more construction firms become accustomed with these new building techniques. But, he adds, there is no federal tax incentive for passive house construction, as there is for renewable energy projects.