Green Building Tour: Cape Cod Ark Offers Fully Functioning Ecosystem

Earle Barnhart shows visitors the “bioshelter” in his home at New Alchemy Farm. PHOTOGRAPHS BY BRENT RUNYON/ENTERPRISE

FALMOUTH- “We live with it. We don’t live in it,” said Earle A. Barnhart about the “bioshelter” attached to his home.
Mr. Barnhart and Hilde M. Maingay’s home is the Arkhouse at New Alchemy Farm in Hatchville. It holds an entire living ecosystem, a solar power station, and much more. It was just one of a dozen houses in Falmouth open to the public Saturday as part of the annual Northeast Sustainable Energy Association Green Buildings Open House tour.
Some of the features in the Barnhart/Maingay home are a three-kilowatt grid-tied photovoltaic system with battery backup, solar hot water, and composting toilets. But perhaps the most remarkable feature is the 1800-square-foot super-greenhouse they call “the Cape Cod Ark Bioshelter.” Surrounded on three sides by glass walls, the bioshelter contains aquaculture systems that produce edible catfish, vegetables, lemons, and herbs year-round in an ecosystem that is inhabited by frogs, insects, and hummingbirds, among other creatures.
The living ecosystem, delicately balanced and perfected over three decades, was originally built in 1976 by the New Alchemy Institute as an “exploration of ideas of solar heating, winter food production, fish farming, and indoor ecological agriculture.”
Everything works together, circulating thousands of gallons of fresh water between nine above-ground fish ponds. Eventually, they use the nutrient-rich water to irrigate crops and other plants. The water also stores heat during the day and releases it at night, passively heating the rest of the bioshelter.

Aquaculture at New Alchemy Farm in Hatchville.

Walking up a stone path, visitors to the Barnhart-Maingay house Saturday were greeted by a handwritten sign that read, “Come right in.”
Inside, natural light reflected off sustainable bamboo floors as a visitor remarked on the smell of baking bread. Decorative glass is set in transoms above the doorways designed to let the natural light filter from room to room.
The first stop on the tour was the basement, which, instead of being dark and damp, was dry and filled with natural light.
Mr. Barnhart and Ms. Maingay excavated a large outdoor area and installed French doors and several sets of windows to let the light in.
Around a corner, past a much-used bread machine and a Ping-Pong table, Ms. Maingay explained the utility closet’s features to a father and his young daughter who were on the tour.
Ms. Maingay explained that the power conversion center in the basement is tied to the photovoltaic solar panels on the roof, which are also connected to the NStar power grid.
At that moment, Ms. Maingay noted that her home was “buying” seven amps from the grid. She expressed concern that they were using so much energy, and flicked off a set of lights in the outer room. Now the meter read two amps, and Ms. Maingay told her guests that the refrigerator must be on.
She said, “When we use electricity, our meter runs forward. As soon as we have more electricity than we’re using, the meter runs backward.”
She told a story about an electrical inspector who visited their home in 2000, when it was completed. She looked up at one of the compact fluorescent lights, the energy-efficient light bulbs that illuminate the utility closet. “He had never seen a CFL before,” she told her guests. “We’ve come so far.”
Behind her, three toy trucks sat upon a 1,422-gallon water tank that stores the solar hot water for showers and circulates it under the floorboards, heating the home during the coldest parts of the year.

The “bioshelter” at New Alchemy Farm is a giant greenhouse attached to an eco-friendly home.

As Ms. Maingay and her tour moved onto the next room, the power conversion center meter showed the home was at that moment using zero amps from the grid.
The windows and doors in the basement are covered with a thin plastic insulating layer, Ms. Maingay explained, which can be bought at any hardware store and helps keep in the heat. She also says it is the cheapest and easiest thing someone can do to make their home more cost efficient.
Heading upstairs, Ms. Maingay explained that they designed their home with their son Ate Atema, a New York City architect, over two years, but that the actual construction was very quick. They used a Canadian company called Marcoux Modular Homes, because the company is Energy-Star-rated. The home was constructed in five days in a factory, shipped in four sections on trucks and assembled on site in just two days.
Ms. Maingay pointed out that the home was oriented from east to west so that the morning sun heats and lights the office area, and that in the afternoon the master bedroom gets most of the light and warmth. This system, called passive solar heating, is used throughout the home and also the greenhouse.
A guest noticed two light blue rectangles in the ceiling, and Ms. Maingay said it was always her dream to have skylights in her bedroom so she could see the moon at night, but when she actually got them, she said, “the moonlight kept me awake.” So she covered them with colored panels.
In the kitchen, natural light filled the space. The sound of running water drifted from the open doors of the greenhouse, or bioshelter, where Mr. Barnhart sat at a round table near a goldfish swimming in a globe.
Mr. Barnhart said the home costs “almost nothing [to run] in the summer.” The concept, he said, “was to put a lot of savings into [new technologies], so we’d have low living costs later.”
In light of the recent drops in the stock market, Mr. Barnhart said, “it was a good move for us.”