case studies
Built for the Cold Passive Solar Home in North Carolina’s Coldest Climate Zone BY LEIGHA DICKENS here’s something special about the North Carolina High Country. Home to ski lodges, Christmas tree farms, and quaint downtowns, these remote and rugged mountains offer the perfect place for tranquility and solitude. Tranquility and solitude were just what Jim and Deb were looking for in their new home. Having spent 13 years traveling in and living out of an Airstream, simplicity had become a way of life for them. They wanted to translate that way of life into a permanent, ecologically friendly home on a high-elevation piece of south-facing land in Ashe County in the northwest corner of North Carolina. Energy nerds will recognize the area as a cold weather anomaly in our state, with mild summers and a winter more akin to what you might find in Ohio or Pennsylvania
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rather than in the rest of the south. Building practices designed for cold climates would be necessary to ensure the frugal-energy living that Jim and Deb sought with their home.
A systems-built approach Jim and Deb selected the “Ridgeline” shell package offered by my company. Based on the net-zero home lived in and designed by Matt Vande of Vandemusser Design, the structural shell components, including open-stud wall panels, roof trusses, and floor trusses, are pre-assembled in our facility in Asheville. We focus on sustainable manufacturing practices, using renewable site electricity to power our operations, and offsetting the carbon associated with shipping our homes to the jobsite through Appalachian Offsets. The layout is optimized for pas-
sive solar heating, featuring a long south-facing main wall and clerestory wall in which to locate thoughtfully sized windows and overhangs designed to shade these windows in summer but leave them open to accept heat gain in winter. With an interior tile floor and stone accent wall offering thermal mass, a high solar heat gain Low-E coating was selected to harvest the maximum amount of heat from these south-facing windows. The wall system uses 2x6 framing, plywood sheathing plus one inch of exterior insulation and drainable housewrap, offering increased R-value and moisture durability. The roof and floor truss system offers deep trusses for thick insulation levels, and uses a raised-heel truss design. Building the key structural components of a home in a factory allows for very precise construction tolerances,
resulting in a structure that fits together very well with few cracks and gaps, further delivering air tightness. Plus, keeping those components indoors until it’s time to go up on site reduces their exposure to the elements, while building in a factory and using parts and pieces sized to match the available sizes of common building materials allows for greater material efficiency. Throughout the build, the project had no need to keep a traditional dumpster on site, and only had to haul waste away from the jobsite four times. For the foundation, which would be part heated space, part garage (to house the Airstream, of course), Jim and Deb likewise chose a systems-built approach, using a precast and pre-insulated concrete foundation system. The result was a structure that became “dried in” within just a few weeks,
A passive solar home in the woods near Boone, N.C. RYAN THEEDE PHOTO
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