Sleep inside one of Japan's most extraordinary sustainable homes. PEANUTS NEST is the concept house of HUCOS, a Japanese builder specializing in passive design using natural materials. Every detail of this home was built to demonstrate a new way of living — one that works in harmony with nature. Constructed with locally sourced Japanese cedar, the house avoids plywood and gypsum board entirely, while carefully minimizing the use of concrete and plastic throughout. Built into the walls is recycled Matsushiro stone — a local material repurposed as a natural thermal mass. During the day, it quietly absorbs heat from sunlight; through the night, it slowly releases that warmth back into the room. A natural battery, built into the architecture itself. Heating and cooling is provided by the PS HR-C radiant system — a water-based panel technology with no fans, no airflow, and no noise. Rather than blowing conditioned air, it radiates warmth or coolness evenly across the room, much like the gentle heat of winter sunlight on a wall. The result: no dry air, no drafts, no mechanical hum — just a quietly comfortable environment. With Japan's highest insulation rating (Grade 7), the home stays warm through Nagano's cold winters with minimal energy use. A stay designed not just for comfort, but to experience a new way of living. Located in Matsushiro, a historic castle town of the Sanada clan, just 25 minutes from Nagano Station.

For nearly 50 years, we have been building homes in Matsushiro, Nagano — guided by a single belief: that people and nature are better when connected. PEANUTS NEST is the home we built for ourselves first. A place where we could put our own philosophy into the walls, the floors, and the air itself — and invite others to experience it. We hope your stay feels less like a hotel, and more like a glimpse of a different way of living. If you have any questions before or during your stay, please don't hesitate to reach out.

PEANUTS NEST is located in Matsushiro, a historic castle town that flourished as the domain of the Sanada clan. The neighborhood retains a quiet, timeless atmosphere, with traditional townscapes, samurai residences, and temples all within walking distance. Standing directly in front of the property is Mt. Minakami — a cone-shaped lava dome known as "the world's oldest pyramid." Mysterious and striking, the mountain draws visitors for its panoramic views of the North Shinshu Alps from the summit. Matsushiro is also home to the Matsushiro Underground Imperial Headquarters (Zosan Underground Bunker), a remarkably preserved WWII tunnel complex built in 1944 as a wartime fallback for Japan's Imperial command. A rare and thought-provoking piece of history. Several quality hot spring facilities are located nearby, perfect for unwinding after a day of exploring. Access is excellent — just 5 minutes from Nagano IC. From here, major destinations across Nagano are easily within reach: - Zenkoji Temple: approx. 25 min - Jigokudani Snow Monkey Park: approx. 45 min - Matsumoto: approx. 50 min - Hakuba: approx. 60 min The town center has local restaurants and supermarkets, making PEANUTS NEST an ideal base for both short getaways and longer stays — quiet enough to rest, well-connected enough to explore.