Kazuyo Sejima and Ryue Nishizawa, who set up SANAA 30 years ago, talk about how nature is both the context and inspiration for most of their work and how they aim to make architectural spaces where people come together
The award of the 2025 Royal Gold Medal to SANAA partners Kazuyo Sejima and Ryue Nishizawa honours an extraordinary body of work. Their buildings are diverse but with common qualities: boldly innovative, refined – sometimes to the point of near-immateriality – and both planned and realised with diagrammatic clarity, suggesting rare confidence and determination. And yet talking to the pair – via video call from their Tokyo studio – they are strikingly self-effacing.
When I ask, for example, if they might use the medal win to broadcast ideas that are close to their hearts, they offer no bombastic manifesto. ‘This is just my personal feeling,’ says Nishizawa slowly, ‘but the diversity of history is something important to discuss. We come from Asian history but we learned so much from Le Corbusier, Mies, Álvaro Siza. The question is what is world history, what is local history, what kind of relation do they have?’
The Gold Medal itself, first awarded in 1848, has been a largely European affair until recent years, although the enormous influence of Japan on modernism was perhaps belatedly and indirectly reflected in medals for Kenzō Tange in 1965, his student Arata Isozaki in 1986, Tadao Ando in 1987 and Toyo Ito in 2006. Following Ito in receiving the award is particularly gratifying for Sejima, 68, who spent six years in his office at the start of her career before setting up on her own in 1987.
Nishizawa, 58, is also an alumnus of Ito’s office and became an early staff member in Sejima’s practice. In 1995 they co-founded SANAA, initially as a way to enter international competitions. Its work ranges from the Louvre’s offshoot in Pas-de-Calais to a campus for Bocconi University in Milan.
Unusually, however, both also maintain their own individual firms, with a separate staff and healthy portfolio of commissions. The Office of Ryue Nishizawa is responsible for a range of public buildings along with radical residential projects such as the 2005 Moriyama House – 10 freestanding rooms in a garden, like a microcosmic town, for a hermetic book-lover. Kazuyo Sejima & Associates, meanwhile, found early fame with equally unconventional schemes, such as a huge slab of apartments at Gifu (1998) that is just one room deep. More recently, it has spearheaded the culture-led regeneration of Japan’s Inujima island, and delivered a 10-unit housing scheme in Kyoto, sheltered by a single lightweight roof broken into 21 angled planes, like a patch of flaking paint.
Having multiple architectural identities benefits both the individual partners and their joint projects. ‘There is a big advantage to working in my own office and with Sejima-san,’ says Nishizawa, as his partner nods in agreement, ‘because the way you imagine space or structure is very different depending on who you collaborate with, and there is a diversity of the quality of imagination.’
Although SANAA is now around 50-strong with five partners, the founders continue a close dialogue. ‘We are bigger and busier but for us, nothing has changed,’ says Sejima. ‘Originally meetings always happened together, but recently I might talk to a project team early in the morning, and he comes back at night to meet the same people. So the staff must have double meetings but we can both remain involved in the process from the start.’
It’s clear that the nature of the work takes enormous commitment – especially given its spread over four continents. Our conversation takes place at 9pm JST and the office is still lively. In the past, they routinely toiled till long after midnight, taking brief catnaps on a daybed in the middle of the studio.
Today, says Nishizawa, the intensity has eased a bit. ‘People do go home at night,’ he says. ‘But we appreciate working very hard during the day’. And while energy levels might decline somewhat with age, Sejima notes with a smile, that is offset by accumulated wisdom.
Their long-established design process – developing ideas through sketch models rather than in computers – makes it easy to keep track of what’s going on. Like many Japanese architects, they prefer paper models, and scores of delicate maquettes dust the surfaces of the office like confetti.
‘Sketch models by western architects often come with a sense of materials, whether that’s wood, stone or plaster,’ says Nishizawa. ‘For us, a study model is not a thing, it’s an idea. Paper is easy to destroy, easy to recreate, and you can produce so many all at once.’
In traditional Japanese architecture, of course, paper is also a building material, and Sanaa’s buildings typically give contemporary expression to similar qualities: physical lightness, transparency and apparent simplicity. The Naoshima Ferry Terminal (2006) comprises little more than a vast roof, just 150mm thick, atop plate glass walls.
British visitors had a taste of this dissolving immateriality at the 2009 Serpentine Pavilion – SANAA’s only built project in this country – where the amorphous form of a 26mm-thick reflective aluminium roof was woven between the trees of Kensington Gardens like a low-flying cloud, supported only by a handful of 50mm-diameter columns.
Pavilions are not subject to the same regulations as SANAA’s large public buildings in Europe and the USA, which are stricter on things like insulation than in Japan. I wonder if the work there might inevitably be ‘compromised’ but the architects see things exactly the opposite: overseas commissions are opportunities to do things that wouldn’t be possible at home, whether that’s the nature of French concrete or using the skills of American carpenters at Grace Farms, where wood lines the soffit of a cultural centre that winds down a Connecticut hillside like a liquid stream.
‘Each place has its own special ways, and this is something we love a lot,’ says Sejima. ‘So every time, the concept is the same but how to realise it is slightly different.’
It is those consistent principles, says Sejima, that give rise to the widely admired physical qualities of their buildings. Transparency, ethereal lightness and the play of reflections are not ends in themselves but the means to an end that is essentially social. ‘People describe our buildings in terms of their physical or visual qualities,’ says Sejima, ‘but our aim is more to make architectural space where people come together.’ Discussing the motive force of projects, the pair talk of non-hierarchical space, of shifting relationships between individuals and groups, and seeking some freedom in plans so that use can reshape buildings over time.
Transparency is also used to connect a building to its surroundings – something that has become a more central preoccupation over the last 20 years since completion of the 21st Century Museum of Art, Kanazawa. There, a variety of box-like galleries sit within a 112.5m-diameter circular building that forms a glazed, publicly accessible route around the perimeter, open to a park.
‘From that project, we learned a lot,’ says Sejima, ‘and maybe tried to make architecture in a less abstract way that is more physically connected to its environment.’
Relatively few SANAA projects address an urban setting, though Sydney Modern Museum (2023) is one notable exception. The stacked pavilions perch atop two existing industrial structures, albeit in a park. ‘I like that project because in some photos it’s hard to see what belongs to our building and what is the context,’ says Sejima.
Nature is not only the context for most of their work but also an influence on buildings. ‘In Japan at least, there is a feeling that architecture comes from landscape,’ says Nishizawa. ‘This is not only about architectural form but the way we think about the set-up of furniture in a living room. We often try to create an interior landscape like a garden or a park.’
A prime example is the Rolex Learning Centre in Lausanne, Switzerland (2010). The upper storey of this university building is arranged as a single 10,000m2 room with a floor that undulates like desert dunes. The idea, says Nishizawa, is that managing the relationship between different activities doesn’t require walls but subtler geographic cues. ‘You can meet in a valley and there you don’t have to work hard to move on to the next programme. With a hill, there is some distance but you will go over if you need to meet different cultures.’
The same story lies behind all of SANAA’s work: the imaginative pursuit of practical aims, without preconception, produces unique outcomes that transcend mere problem-solving.
It is an achievement recognised in the award of the Gold Medal. In his citation, RIBA president Muyiwa Oki lauded SANAA’s consistency in marrying functional rigour and atmospheric power. And when I ask the architects what has given most satisfaction over their long career – and what they still hope to achieve – the typically modest answer is that they have set a course, and stayed it. ‘It is 30 years since we started and the thinking is the same, but we learn and find something new in each project,’ says Sejima. ‘I only hope that we can continue in the same way.’