Emanuele Almagioni wanted to build a home in a cold and windy, but very sunny, town high in the Italian Alps that would use the sun to provide all of its heating needs. With winter low temperatures reaching -25°C (-13°F) the home had to be tight enough to hold the heat, but exposed enough to capture the sun.

So he built a very tall, thin, 3-story wooden home with an all-glass southern facade for maximum sun exposure and nearly completely closed on the other three sides for maximum insulation.

Besides the benefits of the greenhouse effect of all the glass, he also added phase change material (PCM) in some of the windows to absorb the sun’s warmth during the day and then release it at night. The PCM windows are four layers that include a substance with a low melting temperature which melts as it absorbs heat during the day and at night it releases that warmth as it solidifies.

The home is nearly all wood, using prefab OSB panels for structural support and as interior cladding and locally sourced, untreated larch as exterior cladding. Heating is supplied by the sun’s energy and on the rare days when the sun isn’t shining, there’s a wood-burning stove that also doubles as a stove (though the space is so well-insulated that with 2 hours of burning, the home is usually warm for the day). Almagioni used recycled materials for much of the furniture, in particular, wine boxes for kitchen and bathroom cabinets and bedside tables.

Located in an Aosta Valley Italy village (winter population: 5) at 1750 meters above sea level (5740 square feet), the home mimics the passive solar orientation of the centuries-old homes in the village. Almagioni (Studio Albori) was inspired by the vernacular architecture here, particularly the ubiquitous porticos which absorb sunlight and protect from the wind.