Editor’s note: This story is by Jon Kalish, a freelance reporter and radio journalist, based in New York City.
Construction is nearing completion on a net zero house in Warren that is made almost entirely of concrete.
Architect Dave Sellers, whose nationally renowned studio is also in Warren, designed the 1,800-square-foot structure on Prickly Mountain, which has been dubbed the Home Run House.
The use of concrete for a net zero house is as unusual as the financing scheme for this project: It’s being built with a $1 million tax-deductible contribution to The Madisonian Museum of Industrial Design, the nonprofit institution Sellers founded in Waitsfield.
“The museum is supposed to show unique, artistic and well-functioning uses of materials,” Sellers said. “It dawned on me that the museum could demonstrate how responsible we can be using the resources of the planet.”
Funds to build the Home Run House came from Jack Wadsworth and John McQuown, two wealthy northern Californians whom Sellers describes as environmentalists with “some philanthropic capabilities.”
Sellers’ focus on sustainability dates back to the mid-1970s. Named to Architectural Digest’s list of Top 100 Architects in the World, Sellers was named a fellow at the American Institute of Architects earlier this year, an honor awarded to members who have made significant contributions to the profession.
Sellers said he spent a year and a half designing the Home Run House, which has been under construction for two years. The 78-year-old architect is known for his improvisational approach to architecture and this all-cement domicile is being built very much in that tradition.
“This was not designed, ‘Here’s the drawings and go build it.’ It’s a big learning curve,” Sellers explained.
The house has 600 square feet of photovoltaic panels to generate electricity. Space heating is accomplished by a variety of means, including passive solar via 18-foot high windows in one portion of the roof, and geothermal energy from pipes underneath the house. The concrete for the structure will act as a large thermal battery to store heat and radiate warmth throughout the day. There’s a 120-square-foot space for plants to grow out of dirt-filled plastic containers. A rain water collection and drip irrigation system will nourish banana trees, tangerine trees or possibly pineapple plants, Sellers said. The walls on opposite ends of the house roll or swing open for cooling.
According to Sellers, the local building trades people are having a blast. The concrete contractor has enjoyed forming a curved stairway, curved beams and a concrete bathtub in the Home Run House.
“The local crafts people kept saying, ‘Hey, any more cool stuff to make?’” said Sellers.
The house features a number of quirky facets, including an 800-pound wall that slides open to the outdoors with a combination of skateboard wheels and stainless steel wheels. A pair of 14-foot-by-14-foot windows above the plants swing open on a custom-made hinge. Another hinge opens an 8-foot-square wall panel, a task Sellers relished doing with just his pinky.
“When I first walked up here, I’m going, like, ‘Wow, this is crazy,’” said Pierre Jaubert, a carpenter with the Stowe-based contractor Gristmill Builders. “But it all made sense in the end. It’s all fitting together, bit by bit.”
This is not the first concrete house Sellers has built. In 2013 as part of a course titled The Joy of Concrete at the Yestermorrow Design/Build School in Waitsfield, his students started building an 1,100-square-foot cement structure on the grounds of his architecture studio in Warren. Dubbed The Archie Bunker, the house was finished by Sellers’ staff. A fire started during an Airbnb visitor’s stay destroyed the interior in 2016, but the Archie Bunker is expected to begin receiving guests again this winter.
Sellers’ firm is well known for working with plywood, but he’s developed a great admiration for concrete.
“It’s an amazing material,” he said. “You take a liquid that comes up the road in a giant bucket and you dump it into whatever your form is. The next day it’s a 1,000-year-old rock.”
Some in the green building world have suggested that the carbon footprint of an all-concrete house is huge because so much energy is expended in manufacture of cement, which is mixed with water and sand or gravel to make concrete.
George Harvey, a Brattleboro-based writer for the Green Energy Times, acknowledges that concrete is an extremely useful material that is adept at air sealing, one of the major challenges in a net zero house. And Harvey says the lasting power of cement has to be taken into consideration when calculating the material’s carbon footprint. Because the Home Run House is said to be maintenance-free for 500 years, Harvey says it’s the equivalent of eight conventional houses.
“When that [comparison] happens, the amount of energy that goes into that cement in the manufacture of that house becomes much less significant,” said Harvey. “Clearly, this architect has done his homework. It’s not a good idea to say never use cement because there are places where cement is just dandy and this sounds like it might be one of them.”
Architecturally, the Home Run House has a whimsical style. What Sellers refers to as swoopees — curved window shades that extend out from the top of the windows — are among the stylistic flourishes incorporated into the house along with a curved balcony and 2-inch-square holes filled with blue glass tiles. The architect used recycled quarter-inch thick slate blackboards to cover a few of the interior walls. In the mudroom, plywood forms from the concrete pour remain in place for hooks to hang keys and skis. In addition, craftsmen made counters out of concrete.
Sellers said he expects construction to be completed in late September, and he already has a buyer.
Proceeds from the sale would be used to build another concrete net zero house.
“We’re going to take everything we learned from this and do another one,” said Sellers. “I can’t wait.”