A three-story timber extension enhances a hillside home by creating an independent yet connected living space. Situated on a compact, sloping plot, this vertical structure complements the existing residence and serves as a dedicated unit for the next generation.
The extension rises like a slender tower, featuring a striking roof with a diagonal ridge and staggered eaves that emphasize its height. Combining untreated wood and framed mountain views, the extension offers a sustainable retreat for multigenerational living. The design contrasts with the horizontal orientation of the original building while asserting a unique presence. The architecture of this timber extension follows a clear, logical progression that deeply engages with its natural surroundings. Despite its compact size, the timber house maximizes spatial efficiency, resulting in an airy, open atmosphere.
Natural light and framed views
Large windows punctuate the facade, offering framed views of the alpine landscape and establishing a strong connection between interior spaces and nature. Thoughtfully positioned openings bring in natural light, accentuate seasonal changes, and create a dialogue between indoors and outdoors.
These windows fill the interiors with natural light and serve to highlight the subtle, changing beauty of the seasons, immersing residents in their environment. Vertical circulation within the home allows for an efficient use of space, enhancing both privacy and openness.
Integrated climate strategy
The rooftop of the extension hosts a discreet photovoltaic array, supporting the building’s energy needs through renewable means. Inside, the use of clay plaster aids in regulating indoor humidity, contributing to passive thermal comfort and reducing dependence on mechanical systems.
To further enhance efficiency, a brine-to-water heat pump with deep boreholes has replaced the previous oil-based heating system. This upgrade now serves both the existing and new structures, providing reliable heating in winter and the option for cooling in summer, ensuring year-round comfort with a reduced environmental footprint.
Material strategy: timber and earth
The 42-square-meter extension is built entirely above ground in timber—a renewable, carbon-sequestering material that forms the backbone of the project’s ecological approach. From the structural frame insulated with high-performance cellulose to the ventilated façade clad in vertical fir boards, the construction reflects a unified and sustainable use of wood throughout.
This continuity carries into the interior, where fir is used for wall cladding, windows, and doors. Innovative, glueless board stack blanket slabs with acoustic millings enhance acoustic performance while maintaining a low embodied carbon footprint. Clay plaster, applied extensively—particularly in wet areas like bathrooms and toilets—supports passive climate control through its moisture-regulating properties.
Applied over a reed substructure in a 2–3 centimeter layer, the clay finish contributes to a stable and healthy indoor environment, even under humid conditions. Paired with solid wood and natural stone, these materials create a quiet, grounded atmosphere. Each element was selected for its durability, natural aging process, and ability to tell the story of the house over time.
The untreated fir cladding is designed to develop a natural dark patina, allowing the building to blend gradually with its surroundings. Inside, the tactile palette of clay, timber, and stone conveys a sense of permanence and warmth. The project’s integrated material approach has been recognized with a "very good" OI3 classification (OI3-Ic = 1.23) for building ecology in Austria.
