In North Carolina, A Passive Solar Home Gets Active

http://www.motherearthnews.com/green-homes/in-north-carolina-a-passive-solar-home-gets-active.aspx

Robyn Griggs Lawrence thumbnailI fell in love with Asheville, North Carolina, architect Chris Larson’s beautiful passive solar home in Asheville, North Carolina, when we photographed it for Natural Home magazine in 2006. I admired the home’s clean, modernist yet homey design and Larson’s elegant manifestation of his concept of the “sociable kitchen,” which he describes as an evolving effort to identify why kitchens already are sociable places and how they can intentionally be made more so for the enjoyment and benefit of those who inhabit them.”

But a good house is never done. This week Chris sent me word that he’s made his home even better by adding a mother-in-law addition with five solar hot-water collectors that contribute to space heating and provide hot water for the entire house.

Larson’s  2,520-square-foot, three-level home features passive solar heating and passive cooling, slab-on-grade thermal mass with radiant tubing and Icynene insulation. Large south-facing floor-to-ceiling windows in the living room and kitchen bring daylight deep into the interior and blur the distinction between inside and out. “Seeing a great expanse of sky from indoors has the psychological effect of producing a sense of freedom, while looking out these windows into snow and rain is also a inspiring experience,” Chris says. “The flower gardens at the base of the windows function visually as part of the living room, bringing the four seasons inside.”

The home’s windows are shaded with a wooden sunscreen/sleeping deck, sized to provide cool in the summer but allow maximum winter sunlight. The scored and stained concrete floor on the main level stores the winter sun’s heat and releases it during the night, while in summer it absorbs the day’s heat of to keep things cool. Radiant tubes in the main level slab supplement solar heat when necessary.

The house’s height and its pyramidal shape (35 feet from the highest operable window to the lowest) create a “stack effect” that pushes hot air out at the top and pulls cool air in at the bottom, naturally cooling the house without air conditioning. The back side and carport are bermed into a slope for natural insulation, supplemented by Icynene insulation in the walls. A high-efficiency sealed-combustion propane boiler provides back-up heat for extended cloudy periods.

Chris often invites clients and potential clients to his home as a way to help them understand the benefits of passive-solar and sociable kitchens concepts. “A number of my clients have incorporated these ideas, to varying degrees, into their home plans,” he says. “Folks come here and get a direct sense of how a home ‘feels’ when it’s designed following the principles that guide me.”

larson exterior 

Low-maintenance exterior finishes include fiber-cement siding, stucco and a metal roof—all light in color to reflect summer sun. 

larson exterior 2 

High windows at the home's peak provide a "stack effect," allowing warm air to escape and keeping the home cool without air conditioning. 

larson deck 

A large deck shades the home's windows in summer and provides a cool place to sleep. 

larson living room 

Floor-to-ceiling windows let in natural light and the sun's heat to warm the house in winter. Nontoxic paints and varnishes were used throughout the interior. 

larson kitchen 

Larson's "sociable kitchen" has welcoming spots for people to hang out. Interior trim is southern yellow pine, a local softwood. All cabinets are recycled oak, chestnut oak, and heart pine siding from decaying local barns. Granite cutoffs were used for the countertops.  

larson angle addition 

The new addition features 5 4-by-10 solar hot water collectors that contribute to space heating and domestic hot water for the entire house. 

larson addition interior 

The sunny new addition features slab on grade with radiant floor heating and Icynene insulation.