DESIGN /
FEATURES
April 6, 2026
Homes as recovery devices, designed for ultimate well-being.
THE GRANDUO
A five-minute walk from Futako-Tamagawa Station towards the Tama River, and you'll momentarily forget you're in Tokyo. The bustle of the commercial district gives way to the tranquility of a residential area. On this border, a building with a question at its heart has been born.
Introducing the 'Recovery Residence,' featuring the radiant air conditioning system 'THEAR,' Phiten's 'Nano-Metax Technology,' and the world's first island kitchen with air conditioning functionality, 'KUAIR.' Designed with the principles of recovery at its core, 'THE GRANDUO FUTAKOTAMAGAWA' is conceived as a space that prompts the question: 'How shall we live?'
We invite Phiten Representative Director Yoshihiro Hirata, Green Rays Radiant Air Conditioning Engineering Representative Director Junnosuke Fujiwara, and Faith Network Representative Director Jiro Hachiya and Executive Officer Yasuhiro Kuno to discuss this space.
Text by Tsuzumi Aoyama | Photograph by THE GRANDUO (FaithNetwork)
The meaning of luxury is slowly changing. Jiro Hachiya, Representative Director of Faith Network, has been engaging with 'design' for two decades.
Collaborations with renowned architects, a philosophy of unique designs for each residence, and numerous spaces that have garnered international attention. Despite such a wealth of experience, Hachiya found himself unable to let go of a certain question.
Interior view of THE GRANDUO FUTAKOTAMAGAWA.
He dreamed of offering properties so appealing that residents would want to incorporate radiant panels when building their own homes. This had been Hachiya's long-held aspiration for the past eight to nine years.
'As we pursued a high level of design, I realized that design is truly boundless. But more than that, I always felt something was missing. I came to believe that by incorporating elements like light, air, and water 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 spearheaded over 300 'The Granduo' series projects since the company's founding in 2005. As a developer, he has strived to embody the mission of transforming residences into active spaces that extend healthy lifespans.
The Story of Limestone Caves and 'Restorative Air Conditioning'
Japanese summer air conditioning feels like a battle.
'Cafes and trains are freezing, aren't they? Sometimes the cold air hits you so hard in restaurants, you just want it to stop,' laughs Junnosuke Fujiwara, who offers THEAR, an air conditioner without airflow.
Fujiwara explains radiant air conditioning in a remarkably accessible way.
'Imagine a limestone cave. When you enter one, you feel a cool, enveloping sensation, don't you?' says Fujiwara.
Coolness like a limestone cave in summer, warmth like a sun-dappled forest in winter. This is the new value that THEAR brings.
'When you are constantly exposed to airflow, the moisture in your body is gradually depleted. As moisture is lost, your body temperature drops due to evaporative cooling.'
The human body is delicate; even a slight change of 1°C in body temperature can lead to discomfort or reduced activity. Consequently, the body instinctively tries to protect itself, triggering defense mechanisms at the cellular level. Specifically, pores close, muscles tense, and blood vessels constrict.
When this state persists for extended periods, it disrupts the balance of the autonomic nervous system, leading to what is known as 'air conditioning sickness,' headaches, and other ailments. Prolonged exposure to airflow places a far greater burden on the human body than we realize,' explains Fujiwara.
Furthermore, while conventional air conditioners can reduce indoor humidity to 30-40%, the THEAR system tends to maintain it within the comfortable range of 50-60% (※This may vary depending on indoor conditions). A 'non-drying space' offers a different level of comfort for the throat and skin.
The 'Phiten Radiant Heating and Cooling System' used in THE GRANDUO FUTAKOTAMAGAWA is the result of joint research between Phiten and Green Rays, where Phiten's Nano-Metax coating is applied to the surface of the radiant air conditioning panels, and its effects are also infused into the refrigerant circulating within. Standard models offer warmth, coolness, and a comfortable, draft-free experience – that's the effect of air conditioning.
'By adding Phiten's 'restorative' element, it becomes 'restorative air conditioning,'' says Fujiwara. The effect is such that 1+1 becomes 3, 4, or even 10.
Health Measures Move from 'Quitting' to 'Inhabiting' the Home
We want to be healthy, but maintaining a healthy lifestyle is not easy. Yoshihiro Hirata, Representative Director of Phiten, who has observed and researched this paradox for 43 years, offers his perspective.
'Many people start health initiatives but give up midway. When they experience health issues, they persevere until they resolve them, but once they feel better, they tend to slack off.' Therefore, he explains, 'If we are to maintain a healthy lifestyle continuously, the only solution is to improve the living environment itself.'
'What we consider true recovery is returning to one's original state. When stress is prolonged, the body remains in a state of constant excitation. Humans are naturally inclined towards health, so we believe that simply helping the body return to its original state is sufficient,' says Hirata.
In other words, recovery is about removing hindrances, not adding anything.
'Many health-related products prioritize function over design, don't they? We've also struggled with how to make them more aesthetically pleasing,' Hirata admits candidly.
The 'Nano-Metax Coating' applied to the entire walls and ceiling in this project addresses that very issue. Once applied, it functions at the nanoscale, dramatically increasing the freedom in material selection. Furthermore, Hirata found a 'synergistic effect' with radiant heat during his joint development with Fujiwara.
'I felt that the wavelengths emitted by the panels helped alleviate stress from heat, unpleasant feelings, anxiety from cold, and physical stiffness,' says Hirata.
Changing the temperature changes the body's response to temperature. This perspective connected their technologies.
'Aren't we providing an unconscious, comfortable atmosphere that transcends mere heat and cold? Didn't you feel a sense of relief when you entered this room?' asks Hirata.
The Birth of KUAIR: Ten Minutes of Silence
Even the most high-performance equipment is meaningless if it looks out of place in a room. Traditionally, radiant air conditioners were large aluminum panels installed directly on the wall. While functional, they were never aesthetically pleasing, recalls Kuno, Executive Officer of Faith Network.
'I thought they made quite an impact just sitting there in the room. So, I changed my perspective: what if we treated them as furniture? Then, the panels themselves could become a design element,' Kuno explains.
Yasuhiro Kuno (Executive Officer, Planning & Design Department, Faith Network) The implementer who bridges technology and space. For 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,' the world's first island kitchen with air conditioning functionality. Since kitchens are inherently wet areas, they require water and drainage pipes. Similarly, radiant air conditioners need water supply pipes and condensate drainage pipes. KUAIR ingeniously integrates these requirements into a unique product.
The path to completing this project, which intricately involved diverse elements such as kitchen design, architectural design, and air conditioning engineering, was exceptionally challenging. Despite moments of chaos on-site within the tight schedule, the team united to overcome them.
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 creating something that had never existed before. But the desire to make it happen was stronger,' Kuno reflects.
Now, in the top-floor residences, an experience is born: simply standing in the kitchen or sitting in the adjacent living area envelops you in the gentle warmth of radiant heat. You might not consciously notice it, simply perceiving it as a 'comfortably pleasant kitchen,' and that's precisely its success.
All Value Lies in the Unseen
Fujiwara established Green Rays Radiant Air Conditioning Engineering in December 2024.
'I deliberately included 'Radiant Air Conditioning' in the company name. Some told me it was reckless to compete in this field, which has low recognition and high difficulty, but I'm committed to 'popularizing this wonderful air conditioning system,' says Fujiwara.
'THE GRANDUO FUTAKOTAMAGAWA' has achieved the highest S-rank in 'CASBEE,' an evaluation system for building environmental performance, indoor comfort, and landscape quality. It has also obtained 'ZEH-M Ready' certification, awarded to multi-unit dwellings that achieve net-zero (or near-zero) annual primary energy consumption through insulation, energy-saving measures, and on-site renewable energy generation like solar power. The synergistic effect of the external insulation method and radiant air conditioning 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: 'Would a landscape of multiple outdoor units stacked on top of each other be beautiful?'
'I truly feel that more and more residents are appreciating and adopting these unseen values; they are discerning enough to recognize true quality,' says Hachiya.
And Hirata's words encapsulate a dedication bordering on obsession: 'For 43 years, I've been doing the same thing: solving health challenges.'
Phiten, which has honed its technology for 43 years with the singular focus of restoring the body's innate capabilities, 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 to evolve residential living once again.
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 bit 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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THE GRANDUO Official Website