Masonry efficient on Kimberly Knoll: this efficient solar house is just what the doctor ordered.

"I've always wanted a house that combined the needs and living patterns of a modern family with the efficiencies of new building materials," says Dr. Bill Chapman, a pathologist at the VA Hospital in Asheville, NC. "Knowing the limits of energy production, I wanted a structure that would use either solar or geothermal sources of energy in a radiant floor heating system. This building site provided excellent potential for solar heat, but little room for a geothermal field." His new house on Kimberly Knoll Road in Asheville, NC fits the bill. Dr. Chapman highly recommends the in-floor heat throughout the house for its exceptional comfort, and the solar water heating system has met all of his expectations. If he had it to do over again, however, he would choose a different option than the floating wood floor system.

The architect and owner had debated remodeling the original house on the site, which needed some work. It was moldy and uninsulated and built on an unheated slab on grade. They finally settled on building a new house, but they reused some of the original structure's materials like structural steel beams. They're happy with their decision, mainly because the new house has better solar orientation and driveway access. The orientation follows the movement of the sun with passive solar exposure and solar panels on the roof. The driveway access, which was very steep and shady before, is now from a cul-de-sac providing a more convenient entry to the property.

Dodson is an enthusiastic proponent of the "insulated masonry envelope," a highly energy, efficient building method: "Our experience has shown us that a solar house's performance Is maximized by the 'masonry envelope' and slab in-floor heat because of the extra energy efficiency provided by the thermal mass." For this house, she used the Durisol[R] exterior wall system. Durisol[R] is a wall form made out of mineralized woodchips and cement with mineral wool insulation inside the wall form. After the forms are stacked, and horizontal and vertical steel bars are placed, the cavities are filled with concrete. The walls are ten- to twelve inches thick and provide good insulation, thermal mass, great sound-proofing and an eight-hour fire rating. This masonry wall system is non-toxic and uses recycled materials. Chapman likes the masonry system for reasons other than just efficiency: "I sleep very well in my sound-proof house."

During this project, Dodson modified the house design several times in order to meet the owner's changing personal needs. "What brings a project alive is blending the building site's distinct characteristics with the needs and expectations of the occupants," says Dodson. "Orientation to maximize the views and light conditions in relation to the function of space is an important consideration in addition to the technology of the house. As the owner's needs and circumstances change, so too will the house design throughout the design stage."

Top Green Points

Efficiency

masonry wall system offers higher insulation value and thermal mass; solar hot water heat and domestic hot water

Low Toxicity

wall system is non-toxic; natural stucco outside; gypsum wallboard with low toxicity paint

Environmental

wall system made with sustainable, recycled components; reuse of original structure's materials: native plant landscaping

SPECIFICATIONS

Location

Kimberly Knoll Road in Asheville, NC

Designer

Alice Dodson, Architect

Builder

Scott Pillar

Size

3,400 square feet plus two-car garage

Price tag

just under $200/square foot

Completed

2006

Construction type

Durisol[R] exterior wall system