DESIGN /
FEATURES
April 6, 2026
Homes as recovery devices, designed for ultimate well-being.
THE GRANDUO | THE GRANDUO
A five-minute walk from Futako-Tamagawa Station towards the Tama River, and you might briefly forget you are in Tokyo. The bustle of the commercial district gives way to the tranquility of a residential neighborhood. On this borderland, a building has been born, carrying a profound question.
A 'Recovery Residence' featuring the radiant cooling and heating system "THEAR," Phiten's "Nano-Metax Technology," and the world's first island kitchen with air conditioning functionality, "KUAIR." "THE GRANDUO FUTAKOTAMAGAWA" is designed as a space that questions 'how to live,' with the mechanism of recovery at its core.
We hear from Yoshihiro Hirata, President of Phiten; Junnosuke Fujiwara, Representative Director of Green Rays Radiant Cooling Engineering; and Jiro Hachiya, Representative Director, and Yasuhiro Kuno, Executive Officer, of Faith Network, as they discuss this space.
Text by AOYAMA Tsuzumi | Photograph by THE GRANDUO (FaithNetwork)
The meaning of luxury is slowly changing. Jiro Hachiya, Representative Director of Faith Network, has spent 20 years confronting 'design.'
Collaborations with renowned architects, a philosophy of unique design for each residence, and numerous spaces that have garnered attention both domestically and internationally. Despite this extensive experience, Hachiya found himself unable to let go of a certain question.
Interior image of THE GRANDUO FUTAKOTAMAGAWA.
I want to offer properties that would make residents think, 'If I were to build a home, I would definitely want to include radiant panels,' he says. This had been Hachiya's dream for the past eight or nine long years.
"As I pursued a high level of design, I realized that design truly has no limits. But more than that, I always felt something was missing. I came to believe that by incorporating light, air, and water—elements we've been experimenting with—into a residence, we could truly create a space where people would want to live," says Hachiya.
Jiro Hachiya (Representative Director, Faith Network) A visionary who has led the "THE GRANDUO" series for over 300 projects since the company's founding in 2005. As a developer, he has strived to embody the proposition of transforming homes into active spaces that extend healthy lifespans.
A Tale of Caves and 'Balancing Air Conditioning'
Japanese air conditioning in the summer feels like a battle.
"It's freezing in cafes and on trains, isn't it? Sometimes the cold air hits you so hard in restaurants, you just want it to stop," says Junnosuke Fujiwara, who offers THEAR, an air conditioning system without airflow, with a smile.
Fujiwara explains radiant cooling and heating in a very accessible way.
"Imagine a limestone cave. When you enter, you feel a cool sensation, as if you're enveloped in a gentle chill," says Fujiwara.
Coolness like a limestone cave in summer, warmth like a sunlit forest in winter. This is the new value that THEAR brings.
"When you are continuously exposed to airflow, the moisture in your body is gradually lost. As moisture is lost, your body temperature decreases due to evaporative cooling.
The human body is delicate, and even a slight change of 1°C in body temperature can lead to physical discomfort or reduced activity. Therefore, the body instinctively tries to protect itself, triggering defense mechanisms at the cellular level. Specifically, pores close, muscles stiffen, and blood vessels constrict.
If this state persists for a long time, it can disrupt the balance of the autonomic nervous system, leading to what is known as 'air conditioning sickness,' headaches, and other ailments. Continuous exposure to airflow places a greater burden on the human body than we realize," says Fujiwara.
Furthermore, while conventional air conditioners can lower indoor humidity to 30-40%, the THEAR system tends to maintain it within the comfortable range of 50-60% (※varies depending on indoor conditions). A 'non-drying space' offers a different level of living environment for the throat and skin.
Phiten radiant cooling and heating system. Panels installed indoors regulate the temperature of the space.
Health Measures Integrated into the Home, Not Abandoned
We want to be healthy, but maintaining a healthy lifestyle is not easy. Yoshihiro Hirata, President of Phiten, who has observed and researched this paradox for 43 years, has this to say.
"Many people start health initiatives, but most give up halfway. When they experience health problems, they try hard to resolve them, but once they feel better, they tend to slack off." Therefore, he has long believed that "if one wants to maintain a healthy lifestyle consistently, the living environment itself must be improved."
Yoshihiro Hirata (President, Phiten) A leading figure in relaxation and recovery, who has researched and evolved Phiten's unique "water-soluble metal technology" for 43 years. He is now challenging himself with a new endeavor: implementing the technology cultivated through conditioning professional athletes into entire living spaces.
"What we consider true recovery is about returning to a baseline state. When exposed to stress for extended periods, the body remains in a state of constant excitation. Since being healthy is the natural state for humans, we believe that simply returning the body to its original condition is sufficient," says Hirata.
"There are many health-related products where functionality takes precedence and design is an afterthought. We also struggle with how to make them more stylish," Hirata admits candidly.
The "Nano-Metax Coating" applied to the entire walls and ceiling in this project has resolved that issue. Once applied, it functions at the nanoscale, dramatically increasing the freedom in material selection. Furthermore, Hirata felt a 'synergy' with radiant heat during his joint development with Fujiwara.
"I felt that the wavelengths emitted from the panels help alleviate stress from heat, feelings of discomfort, anxiety from cold, and physical stiffness," says Hirata.
Installation example in a bedroom. Unlike the living room, white panels matching the room's interior have been installed.
Changing the temperature changes the body's response to temperature. This perspective connected the technologies of both.
The Birth of KUAIR: Ten Minutes of Silence
No matter how high-performance the equipment, it's meaningless if it looks out of place in a room. Traditionally, radiant cooling and heating units were large aluminum plates installed directly on the wall. While functional, the design was never satisfactory, recalls Kuno, Executive Officer of Faith Network.
"I thought that placing it directly in the room would have a significant impact. So, I changed my perspective and thought, 'What if we treated it like furniture? Then the panel itself could become a design element,'" says Kuno.
Yasuhiro Kuno (Executive Officer, Planning & Design Department, Faith Network) The implementer who bridges technology and space. In this project, he conceived and realized "KUAIR," the world's first island kitchen integrated with radiant panel technology, achieving both design and functionality.
This led to the creation of "KUAIR." It is the world's first island kitchen equipped with air conditioning functionality. Since kitchens are inherently wet areas, they require water and drainage pipes. Similarly, radiant cooling and heating units need supply pipes and drain pipes for condensation. KUAIR is a unique product that rationally integrates these functional requirements.
The path to completing this project, which intricately involved diverse elements such as kitchen design, architectural design, and air conditioning engineering, was exceptionally challenging. There were moments of confusion on-site due to the tight schedule, but the team tackled and overcame them together.
THEAR panels are also installed in the island kitchen, offering a solution with high drainage efficiency and effective air conditioning for the living area.
"Of course, it was difficult because we were creating something that had never existed before. But the desire to make it happen was stronger," Kuno reflects.
Now, in the top-floor residences, simply standing in the kitchen or sitting in the living room nearby envelops you in the gentle warmth of radiant heat. If you don't consciously think about it, it's just a 'comfortably pleasant kitchen,' and that's precisely the point.
All Value Lies in the Unseen
Fujiwara established Green Rays Radiant Cooling Engineering in December 2024.
"I deliberately included the term 'Radiant Cooling and Heating' in the company name. Some told me it was reckless to compete in this field, which has low recognition and high difficulty, but I am committed to 'popularizing this wonderful air conditioning system to the world,'" says Fujiwara.
"THE GRANDUO FUTAKOTAMAGAWA" has achieved the highest S rank in "CASBEE," an evaluation system for building quality that assesses environmental performance, indoor comfort, and landscape. Furthermore, it has obtained "ZEH-M Ready" certification, awarded to collective housing where the net annual primary energy consumption is zero (or close to zero) through insulation, energy-saving performance, and energy generation from solar power. The synergistic effect of external insulation and radiant cooling and heating reduces environmental impact while enhancing residents' well-being.
Both THEAR and KUAIR are water-cooled systems, meaning only one outdoor unit is needed for every five panels, a significant advantage. This also provides an answer to Hachiya's long-standing question: 'Is the sight of multiple outdoor units stacked on top of each other beautiful?'
"I truly feel that more and more residents are appreciating and adopting 'invisible value.' They are discerning enough to recognize true quality," says Hachiya.
And Hirata's words, which could be described as a lifelong pursuit, encapsulate this: 'For 43 years, I have been doing the same thing (solving health challenges).'
Phiten, which has honed its technology for 43 years with a singular focus on returning the human body to its natural state; Green Rays, which relentlessly pursues ultimate comfort without airflow or noise; and Faith Network, which has challenged the norms of rental housing in the Jōnan area, have converged, leading to another evolution in housing.
If you were to live here, you might not notice anything at first. Without realizing it, your days would gradually become more balanced. Weeks later, when you think, 'I just feel a little better,' you'll understand the success of this home.
THE GRANDUO FUTAKOTAMAGAWA
2-10-14 Tamagawa, Setagaya-ku, Tokyo 158-0094
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