When you combine Passivhaus with prefab you get one of the greenest buildings possible. Designers Vanda Holescakova of Architectonica and Katarina Husarova Volekova of DSU have conceived the Nest Box, a super-insulated prefab home that can be placed just about anywhere with minimal disturbance of the land. The plans come in several variations, ranging from a tiny apartment to larger combined units for growing families. And best of all, the occupants live in a healthy, low-impact environment requiring practically no energy to stay cozy over a long winter.

Nest Box takes the simple idea of designing modular, prefabricated homes while following the rigorous Passivhaus requirements. The combination of thick walls and triple-pane windows produces very high performing homes with very little air leakage. The thick walls are made from natural materials like cellulose and local wood, with a slab of tongue and groove wood fiber insulation board wrapping the exterior. While owners can choose from an assortment of sidings, the designers are showcasing a clean horizontal wooded slate.

The interiors are arranged to maximize space, with the smallest units starting at a tiny 20 square meters — not an easy feat with Passivhaus. Larger units go up to 90 square meters for multiple bedrooms. Each box is fully insulated underneath as well so they can simply sit on concrete columns, minimizing site disturbance and making them easier to move. The distinctly modern styling is a perfect complement to the energy savings, and with the 45-square-meter unit priced at €70,000 the Nest Box may herald a new age of low-impact affordable homes that meet the strictest of energy savings.