On a forested site in Karuizawa about two hours outside of Tokyo, a city dweller’s peaceful retreat allows her to read, work, and quietly enjoy the tranquil surroundings.

With the forest floor covered in trees, ferns, and wildflowers, Tokyo-based architecture firm Hiroshi Nakamura & NAP carefully considered the impact of the design on the surroundings and its delicate ecosystem. Presented with a sloping site, Nakamura and the team conceptualized a design that would be nestled into the hillside, minimizing the disruptive effects of site preparation, while welcoming light and warmth from the sun.

The home is partially submerged, and a living roof allows it to become almost undetectable against the forest floor. “We aimed to reuse the wildflowers, soil, and trees that originally existed on the site as much as possible,” explains Nakamura. Above the rooftop, a glass-enclosed lookout appears to puncture the earth—from certain vantage points, it’s the only evidence a dwelling exists beneath.

The glass-enclosed room—a home office—gives observers an intimate vantage point of the natural flora beyond. “The study was set up so you can look out like a cockpit,” explains Nakamura. “The wildflowers are so small that you can’t notice them when you walk around. Rather than looking down on [them], it’s an observation hut where we can interact with [them] from the same perspective.” The homeowner relishes time spent here, working or reading her favorite books, while getting an up-close perspective of delicate plants and flowers just beyond.

Karuizawa, a welcome summer retreat, provides relief from oppressive heat in Tokyo and neighboring cities. Experiencing all four seasons, the region is mild in summer, but can plummet to frigid temperatures in winter. With this fluctuation in mind, the home’s design and orientation was carefully manipulated to employ natural heating and cooling techniques.

“We [designated] various places to live, including approaches and zoning to make the most of the difference in elevation,” explains Nakamura of the home’s hillside positioning. Employing gravity ventilation, air flows through the open living room doors at the lowest zone to the uppermost floors in the summer, keeping the whole home cool and breezy. In winter, heat from the lower-level fireplace is diverted to the main bedroom in the evenings by opening the shoji doors in the upper zone.

The interior of the two-bedroom home is centered around a dramatic kitchen and living room, which fully opens to the elements, thrusting inhabitants into a canopy of maple, oak, and dogwood trees. From rich teak flooring to locally sourced Asama stone, warm and natural materials were chosen to “blend in without deviating from the context of the site,” says Nakamura. Fluidly assimilating into the forested landscape, the home maintains an intentionally quiet appearance, allowing the beauty of the plants and wildflowers to shine.

Shop the Look

Cockpit in Wild Plants allows the homeowner to intimately observe the changing seasons, from budding flowers in spring to falling leaves in autumn. “Our philosophy was to create a design that was in tune with the topography and nature of the site and the behavior and feelings of the people who work there,” explains Nakamura. “We valued the respect for nature and the experience that is unique to the place.”

Related Reading: This Serene Japanese Retreat’s Overlapping Roofs Look Like Fallen Leaves

Project Credits:

Architect of Record: Hiroshi Nakamura & NAP/ @hiroshi_nakamura_naparchitects

Builder/General Contractor: Takehana Kogyo

Structural Engineer: MI+D architectural structure laboratory

Landscape Design: Shiiaru Club

Other: ZO Consulting Engineers