A Japanese Retreat With a Glass “Cockpit” Places Forest Wildflowers at Eye Level

Camouflaged by a living roof, this sunken hideaway in Karuizawa has a study that peeks out at the surrounding foliage.

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.

In a deciduous forest in the resort town of Karuizawa, Japan, tiny wildflowers grow at the feet of majestic trees. The client "wanted a house that would fit in with this terrain and not destroy the environment," explains architect Hiroshi Nakamura.

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’s simple, cabin-like composition and use of natural materials enable a dialogue with nature. Locally sourced stone forms the masonry wall, which protects the concrete foundation.

A living roof was carefully populated with indigenous plants and flowers. After functional considerations such as waterproofing and drainage were addressed by the contractor, Mitsuko Suzuki of the Shiiaru Club brought in native plants. "The soil is also mixed with the original soil, taking into account drainage and weight," adds Nakamura.

Oak and chestnut trees harvested from the site were used as log posts at the front entrance.

Tucked into the hillside of a southern sloping site, the stepped design finds a balance between sunshine and ventilation. Native plants become a part of the home’s living envelope, "in order to make it look like the earth has been lifted up as it is," explains Nakamura.

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.

Above the grass shingled roof, the protruding glass enclosure is an alluring portal to the dwelling beneath. Surrounding the glass lookout, 50 unique species of wild plants blanket the surface.

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.

Tiger lilies bloom on the roof, and can be quietly observed at eye level from the glass-enclosed "cockpit."

An inspiring place to work or read, the cozy home office features teak flooring, desk, and wall paneling. The warmth and simplicity of the interior allows nature—even the tiniest of life forms—to come into full focus.

The office’s eye-level vantage point offers an up-close-and-personal view of plants and flowers that might otherwise be overlooked.

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. 

In the summer, the expansive living room doors slide open to remove all barriers between outside and in. Through gravity ventilation, air flows in through this large opening in the lowest zone and upwards through the home, keeping it comfortable and breezy.

During frigid winter months, heat from the living room fireplace is strategically routed through the home through the opening and closing of shoji doors. When the fireplace is turned off at the end of the night, upper-zone shoji doors are opened to direct heat to the main bedroom.

The inviting entry corridor features natural Asama stone and pine ceiling beams, along with concealed storage space. Sliding closet doors incorporate doorknobs made from fallen branches found on the site.

A teak bench tucked at the end of the hallway provides a cozy space for reading. In summer, air flows south to north from the lower to upper level, ushering in a pleasant breeze which passes through the window above the reading nook.

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.

Materials for the interior were chosen to foster a relaxed vacation home atmosphere. Teak floors and pine beams create a warmth and easiness in the main living space, while helping to establish a natural dialogue with the forested landscape.

Cozy interiors with simple finishes allow the focus to remain steadily on the verdant natural surroundings. "The house is located in the middle of an overwhelming forest, so we [put the] focus on nature...and the wildflowers on the roof," explains Nakamura.

Shop the Look
Sossego Tereza Stool
counter stool 34.6" H 17" W 19.3" D 24" SH  barstool 40.3" H 17" W 20.7" D 29.9" SH   Hand finished by Brazilian artisans and delivered to you in 8-10 weeks.
Lulu & Georgia Arches Rug in Rust
Featuring a subtle, minimalist design and pretty fringed edges, the versatile Arches Rug is made from 100% wool. Its high-low pile heights adds texture and visual interest to a space.

The lofted master bedroom remains partially open to the living room below, enjoying flexible ventilation and views to the outdoors.

An originally designed handrail is made of round steel wrapped with leather cord.

The materiality of the home is deeply rooted in the immediate natural environment; exterior walls are composed of stone and cedar sourced from the site. 

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."

Cockpit in Wild Plants ground floor plan

Cockpit in Wild Plants second floor plan

Cockpit in Wild Plants section

Cockpit in Wild Plants site plan

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 


Get the Dwell Newsletter

Be the first to see our latest home tours, design news, and more.