With the roof angled at 43 degrees, the architects lined the southern slant of the house with solar panels to collect as many rays as possible. Karanesheva and Witzmann started with four, but then added 23 more, all by Systaïc; the company gave them a deal since theirs was its first installation in France. The panels now collect far more energy than the home actually needs, a precious resource that the pair sells back to the power company.
The home’s central “spine,” which
Witzmann describes as “the back-
bone of the house at a load-bearing
and technical level,” serves as the
structure’s organizing principle. It
groups the ventilation system and the
majority of the electrical networks
together and centralizes much of the
home’s storage. By siting the living
spaces on the south of the house
so that they take advantage of the
natural light, and placing the sanitary
and service rooms on the north, the
architects make the most of a smart
passive solar layout.
Stunning bamboo covers the house on all four sides, its lattice making up a striking set of adjustable screens that allow the residents to modify the facade to suit the weather. Karanesheva and Witzmann tested a host of materials, but bamboo had the aesthetic and green cred they were after.
All told, they hung some 28,000 linear feet of the material with the larger sections composed of around 250 stalks. Each pole is threaded with
galvanized steel wire and separated from the next by a small aluminum spacer. A highly renewable resource, the untreated bamboo has aged over
time; what started as yellow-green has turned into a muted gray just a year after completion.
One key to the home’s efficiency is a tight building envelope that keeps the heat inside. Triple-paned windows by Optiwin (check out the three reflections of the flame below) and well-sealed frames do the trick.
In a nod to what they describe as “constructive truth,” the couple made the decision not to hide the technical elements that contribute to the home’s green attributes. And by displaying all the sustainable features in the walls, it’s “easier for our clients to understand the system when they visit the house,” says Witzmann. They incorporated the Genvex ventilation system’s double-flow ducts into the home’s interior, exposing them at various points as they run through the house. In addition to looking pretty, they distribute clement fresh air; temperatures hover around
66 degrees Fahrenheit in the winter
and 71 degrees in the summer, never going higher than 78. And yes, Karanesheva assures, “you can open the windows of a Passive House.”
The pair selected fluorescents in
the kitchen and dining area for their
energy efficiency, low cost, and
clean aesthetic, echoing the bamboo
screens outside. The Spina pendant
above the table is from Ribag Licht
and complies with very green Swiss