Brian Leussler’s Vermont house doesn’t look like your average wood-framed mountainside home because it’s not.
The north exterior wall resembles an abstraction of the surrounding forest: Corrugated ribbing rises upward like a stand of tree trunks. The south side, which faces a verdant view with sliders and large windows, displays impressions of branches and leaves in bas-relief. Inside, an open-tread staircase projects from a wall of gently curved ribs that arch diagonally across the wall’s expanse.
Leussler’s 1,200-square-foot house is made of concrete, poured on site into fabric molds, which make the voluptuous, rounded shapes possible. It was designed and built by Alexander “Sandy’’ Lawton, founder and president of ArroDesign in Waitsfield, Vt., who has been working with fabric-formed concrete since the 1980s. He calls the home he built Leussler a “climate-resistant house.’’
A CONTROVERSIAL BUILDING PRODUCT
Concrete is an ancient, ubiquitous, and controversial material not usually used in residential construction, except for foundations and slabs. A simple and variable mixture of sand, aggregate, and cement, concrete was famously used by the Romans to build the Pantheon. (Nearly 2,000 years later, this building still houses one of the world’s largest unreinforced concrete domes.) The recipe was lost in the fall of Rome, but in 1824, Joseph Aspdin, bricklayer and mason of Leeds, England, patented what he called “Portland cement,’’ since it resembled the stone quarried on the Isle of Portland. The 1825 completion of the Erie Canal created the first big American demand for concrete.
“Concrete is a simple building material with a complicated manufacturing process,’’ said Amy Lamb Woods, director of training and education at the International Masonry Institute and a licensed engineer in multiple states. She lives in Chicago but specializes in concrete and masonry restoration nationwide. She has studied cement chemistry and is passionate about cement history and the preservation of our historic concrete structures.
“Historically, the cement that binds concrete was derived from shells, clays, or mineral deposits,’’ she said. “When the Erie Canal was built, they used natural cement. Portland cement, however, hardens chemically. Its manufacture uses a lot of energy because it requires very high heat. To the mix, they have added old tires, fly ash, furnace slag, all manner of toxic materials.’’
Making cement accounts for 8 percent of the world’s carbon dioxide emissions, one reason environmentalists oppose it. Concrete is the most used material in the world and has been called “the most destructive material on earth.’’
“There is always a dialogue between wood and masonry construction,’’ he said. “Masonry has a much better thermal quality, but it is true that Portland cement is a troublesome aggregate.’’
Michael Ireland, president and CEO of the Portland Cement Association, said his industry “has increased energy efficiency and reduced emissions in the manufacturing of cement while continuing research and development to reduce its carbon footprint.’’ He said the industry is focused on promoting the broader adoption of Portland-limestone cement in the United States, “which has been proven to reduce greenhouse gas emissions up to 10 percent during the manufacturing process.’’
Lawton is also exploring alternatives to Portland cement, polymers among them.
“Polymers make for a stronger cement, emit 90 percent less carbon dioxide, and use less water than Portland cement,’’ he said. “They can also be an answer to the problem of depleting the world’s sand deposits. But, the process is more expensive: A yard of Portland cement costs $120; a yard of geo-polymers costs $400.’’
He added that the lobbying arm of the Portland cement industry is comparable in strength to that of the fossil fuel industry.
Because of the expense and the still-evolving nature of polymers in concrete, Lawton uses Portland cement in most of his projects. He believes that the strength, longevity, and the passive solar and thermal properties of the finished house outweigh the material’s negative environmental aspects, especially when used in small, carefully measured quantities.
POURED CONCRETE VS. BLOCK
There are countless concrete houses in the southern and western United States, but they are built of concrete block, not poured concrete.
“Concrete block is not good for strength, and it has no thermal quality, so it’s not used in cold climates,’’ Lawton said. “But it’s cheap and easy.’’
Poured concrete for residences, however, has been an outlier.
Perhaps the first non-industrial concrete structure in the United States was of Unity Temple in Oak Park, Ill., designed by Frank Lloyd Wright in 1905. He designed other famous poured-concrete buildings during his seven-decade career.
“The standard way of building houses has always been to add layer upon layer; Wright hated that,’’ said John H. Waters, architect and preservation programs manager at Chicago’s Frank Lloyd Wright Building Conservancy.
“Part of his organic philosophy of architecture was about the integrity of the materials. When poured, concrete is extremely flexible, and Wright made great use of that characteristic at Fallingwater, a family vacation home in southwestern Pennsylvania, the research tower at Johnson Wax headquarters in Racine, Wis., and New York City’s Guggenheim museum.’’
During the early decades of the 20th century, Thomas Edison patented and promoted concrete houses poured in one piece on site. A few were built, some of which stand today, but the venture was a massive failure. His idea, however, was ahead of its time: In Belgium today, concrete houses are being constructed in one piece, the material delivered via 3-D printers.
While wet concrete is usually poured into rigid molds, Lawton uses polyethylene or polypropylene woven fabric. The technique was pioneered by friend and colleague Mark West of Montreal.
“They are the cheapest textiles in the world, yet they are very strong, will not propagate a tear, and nothing sticks to them, including concrete.’’
Brian Leussler’s climate-resistant house began with a steel framework. Lawton fastened insulation to the skeleton, then applied concrete over that. Exterior and interior walls were cast separately, allowing for functional and decorative elements like the interior wall that anchors the stairs.
“The heavy curved patterning of the wall creates a number of perpendicular surfaces to absorb heat,’’ Lawton said.
See more photos of the property below:
HIS HOME AWAY FROM HOME
Leussler is a high school English teacher at Boston Latin Academy. His Vermont house is a vacation home.
“I have been going to Sugarbush to ski for years,’’ he said. “On a recent trip, I saw a concrete house, one of the first concrete structures I have ever seen. It turned out to be designed and built by Sandy. I bought a lot from him, and we began this in 2018. I wanted what I had seen in his other concrete house, including the minimalist aesthetic and the heated floor.’’
His house is heated via radiant heat pipes under the concrete floor.
“I have a 1,000-gallon propane tank in the lawn, and in a closet, an instant hot water heater about the size of a briefcase,’’ Leussler said. “The water circulates under the floor, is totally quiet, heats up quickly, and holds the heat. In the summer, the floors are cold.’’
He tells how, when he returns to Boston after winter weekends and checks the temperature in Vermont on his smartphone, he sees that, after the heater is turned off, the house holds its 70-degree heat for a day and a half.
This ability to hold heat, its passive heating and cooling elements, and the concrete’s strength in the face of high winds is what leads Lawton to call it a climate-resistant house.
It has two full baths, two bedrooms, plus a bunk room. The living room, kitchen, and dining room constitute the great room on the first floor. A steel beam across the ceiling supports the open space. The kitchen island is one massive piece of cast concrete.
A second-story terrace accessed from the bedrooms shades the first-floor windows in summer but allows solar gain in the winter. The green roof is planted with sedums.
“As a teacher, I spend all summer here,’’ Leussler said. “So the outdoor space is very important. This is beautiful, natural, clean, and surrounded by trees.’’
Regina Cole writes about architecture and design. Send comments to [email protected]. Subscribe to our free real estate newsletter — our weekly digest on buying, selling, and design — at pages.email.bostonglobe.com/AddressSignUp. Follow us on Facebook and Twitter @globehomes.