Sustainable Design’s founder Alan Benoit sheds light on the design process behind the award-winning “Net Positive Craftsman” house.
STORY BY BENJAMIN LERNER
PHOTOGRAPHY COURTESY SUSTAINABLE DESIGN
In the heart of Bennington County, a modern marvel of sustainable engineering lies hidden at the end of a gently-curving mountain driveway. Tucked away on a picturesque and quiet hillside overlooking Mount Equinox, the 3-bedroom, 3.5 bathroom 3,200-square-foot “Net Positive Craftsman” house stands as a striking testament to the extraordinary power of ecologically-conscious architecture. The mossy-green color on the outside walls blends seamlessly with the surrounding forest, and the stone walls that line the driveway conjure feelings of sylvan nostalgia.
Completed in 2020, the celebrated home came into being as a result of the remarkable efforts of Alan and Nancy Benoit, the owners and founders of Sustainable Design in Manchester, Vermont. The Benoits first made the decision to open Sustainable Design together after working for years as highly-skilled engineers. “When you work as an engineer, you’re somewhat limited in terms of how you can artistically express yourself,” notes Alan. “I got my first degree in engineering, but I also went to school for art and sociology. Nancy also has an extensive background in engineering.” Although Alan found great fulfillment in his work as an engineer, he was always eager to explore other professional avenues. “I had been passionate about nature since my childhood, and I had also taken classes in landscaping and native plant studies during the course of my educational journey,” says Alan. “One day, I had an important revelation: I realized that I could combine all of my interests together by working as an architect.”
Following his decision to switch career paths, Alan moved to Vermont with Nancy in 2001, where he took a job at the Manchester-based architectural firm Badger and Associates. During his eight-year stint there, Alan advocated for the use of sustainable and energy-efficient materials, such as dense-packed cellulose and recyclable products. Alan left Badger and Associates due to the housing market crash in 2009, and he and Nancy founded Sustainable Design several months later. Today, they work together as a dynamic husband-and-wife team. Alan works as Sustainable Design’s Principal Architect, and Nancy works as their Senior Designer.
Over the following years, The Benoits have worked on a number of innovative and inspiring sustainable housing projects, all of which incorporate state-of-the-art energy efficient technologies and ecologically-mindful design elements. “Whenever you’re designing a home with sustainability in mind, the number one priority is energy efficiency in terms of its design and construction,” says Alan. “It’s also important to make use of renewable energy such as solar power. In addition, you want to use sustainably-sourced materials whenever possible, and you want to make sure that the home is integrated into the landscape.” Alan explains that whenever construction work is done for a home, (whether in the context of a renovation project or a build project) it can often have a significant impact on the surrounding environment. “You can either restore the environment to the way it was before, or you can build it back better,” notes Alan. “Our aim is to go above and beyond to have a positive impact on the local ecosystem and environment in every way possible.”
According to Alan, the Net Positive Craftsman house serves as a shining manifestation of all of the foundational principles of sustainable design. “Every aspect of the house is designed to maximize energy efficiency and minimize environmental impact.” The house is built into a southward-facing hillside, with three stories of large glass windows that allow natural sunlight to heat the home in the colder months. “The house is deceptively small from the front,” says Alan. “You only see one story as you approach, but if you come around the back, you will see two additional stories built into the hillside. We were incredibly fortunate that the property we built on naturally sloped southward. It allowed us to build it in a way that took advantage of passive solar heating.”
The Net Positive Craftsman house also makes use of natural passive shading techniques to increase energy efficiency. “If you go out on a hot summer day and you stand underneath a tree, you automatically feel cooler in the shade because you’re out of the sun,” says Alan. “The same principle also applies to houses. We took advantage of the deciduous trees in the forest around the Net Positive Craftsman house, and we also made sure to incorporate architectural features in the home such as eave overhangs, porches, and decks, which can also be used to create artificial shade.”
Alan says that given Vermont’s cold winter climate, it was important to ensure that the home was properly insulated and thermally broken. Alan elaborates: “All of the features that touch both the inside and outside of a home, such as wooden studs and doors, play an active part in the transference of heat. If the temperature outside of a home is -20°F and the optimal inside temperature is 70°F, you have to create a buffer between the cold outside and warm inside in order to keep it energy efficient. You can do that through a number of insulation techniques, but it’s also important to design a wall that is both air tight and vaper open so that condensation doesn’t get trapped and cause mold, rot or other damage to the home.”
To that end, every part of the Net Positive Craftsman house from its basement to its roof is entirely shielded by multiple layers of continuous exterior insulation. “When a roof and a wall connect, the roof often gets thinner at the convergence point,” says Alan. “Keeping that in mind, we designed the Net Positive Craftsman house’s roof with a feature known as a ‘raised heel truss,’ which raises the roof higher where it meets the wall. This allows us to place insulation at critical places where a lot of energy is lost, and it greatly improves the energy efficiency of the house.”
To prevent gradual water damage in the walls of the home, the Benoits designed an airtight vapor-open wall assembly system to allow moisture to freely travel from one side to another without becoming trapped in the walls. “The temperature inside and outside of the house determines which way the vapor moves through the wall assembly,” says Alan. “As long as you keep the walls ‘vapor-open,’ the vapor can dry in two directions. If the house gets wet on the inside, it allows it to dry on the outside, and vice versa. We accomplish this by putting vapor-open materials beyond the airtight layer, plywood sheathing on the exterior side, and also behind the sheetrock on the interior. In the past, homes were often built with plastic in the walls or with foam on the outer layers of the building. Doing so creates a vapor barrier that traps moisture inside of the wall cavity. As a result, moisture is pushed into the walls for a large part of the year. By getting rid of the foam and plastic and replacing it with vapor-open materials, we’re able to build homes that dry even in the wintertime.”
The energy efficiency of the Net Positive Craftsman home is further enhanced by a ground-source heat pump (which transfers natural heat from the ground into the house) and on-site solar panels, which create enough renewable energy to make the home fully “Net Positive.” In order for a home or commercial building to be considered “Net Positive,” it has to create more energy than it uses. Alan and Nancy say that they are very thankful that they were given the opportunity to work on the Net Positive Craftsman house project, and also grateful to have received a 2020 Vermont’s Greenest Building Award for residential design. “The owner of the property was interviewing multiple architectural before she hired us for the project,” says Nancy. “She had incredibly progressive ideals that directly aligned with ours, so it worked out perfectly. When we first started the project, we never thought that we would qualify for the Vermont’s Greenest Building Award, or that the Net Positive Craftsman house would turn out to be the most energy-efficient home in the state. During the evaluation process, the Vermont’s Greenest Building Award committee reviewed a year’s worth of electrical bills. They found that the home was actually creating more energy than it consumed, which speaks not only to the home’s design, but also the thoughtful energy use habits of its owner. The fact is, you can design a house to be perfectly energy-efficient, but the actual energy efficiency of the home is largely dependent on the people who inhabit it and their lifestyle choices.”
In addition to integrating energy-efficient engineering and design principles into the Net Positive Craftsman House, the Benoits also made use of sustainably-sourced materials in its construction. “The cabinets, floors, and some of the sheathing used in the house were sourced from trees cut down on the property,” says Alan. “We try to use on-site or local materials whenever possible in all of my designs.” In line with The Benoits’ preference for locally and sustainably-sourced materials, the dormers at the front of the house are covered with locally-sourced slate siding, and the exterior walls of the house are covered with cedar shake siding and tulip poplar tree bark siding made by Bark House in North Carolina. According to Alan, Bark House’s tree bark siding is the world’s first “Cradle to Cradle” platinum-certified product. “In order for something to be designated a ‘Cradle to Cradle’ platinum-certified product, it has to be entirely energy neutral at every stage of its existence, from its raw material stage until it is thrown away at the end of its life cycle.”
Alan says that Bark House’s tree bark siding is sourced from trees that are already being cut to make furniture. The bark is taken from the trees after they are cut and laying on the ground, and then dragged by hand back to their plant, where it is cut to size and pressed into flat shingles that are ready for commercial use. All remaining scraps are then composted into dirt that helps to grow the next generation of trees, completing the “Cradle to Cradle” cycle.
Inside of the house, maple and slate floors and cherry wood library shelving create an ambience of rustic ease and comfort. An inviting kitchen surrounded on three sides by open windows provides breathtaking mountain views. Outside, a “pollinator garden” serves as both a sanctuary for local wildlife and a sustainable natural food source for the house’s owner. “The on-site pollinator garden has fruit trees, berry bushes and a rainwater capture, and there is a beautiful wildflower meadow as well,” says Alan. “It gives us great joy to know that the land surrounding the house is being used in a thoughtful and considerate way.”
As the Benoits look towards the future of sustainable architecture, they are encouraged by recent technological advancements and equally enthusiastic about the emergence of sustainably minded companies in Vermont and its surrounding states. “There are a lot of sustainable products that have been used in Europe for years that we have had to import overseas, which creates a large carbon footprint. One of them is wood fiberboard insulation, which has never been manufactured in the United States. There is a plant that is going to begin production this year in Maine, where they will generate wood insulation from scrap pieces of natural trees. Here in Vermont, a company called, Glavel (in Burlington) is going to be opening a plant in November that makes lightweight recycled glass aggregates that are used in sub-slab insulation. There is a lot of work that needs to be done to continue to make an impact, but we learn more with every project, and we’re excited about the future of sustainable design.”