Japanese architect Kengo Kuma has rejected claims he copied Zaha Hadid’s designs for the Tokyo Olympic Stadium
Last week Hadid sent a report to the Japan Sports Council (JSC) outlining similarities between the ‘structure, layout and numerous elements’ of her proposals – which were controversially shelved last summer – and Kuma’s latest competition-winning design.
Hadid’s accusation came after she refused a request from the JSC to hand over the copyright of her scheme in exchange for an overdue final payment.
But Kuma said that Japan’s strict regulatory requirements meant it was inevitable there were some similarities between the two approaches for the 2020 stadium.
Speaking at the Foreign Correspondent’s Club of Japan on Friday (15 January), Kengo Kuma said: ‘When we consider the design is being created within the same land, using the same tracks and under the same laws it is natural and almost automatic that there are some similarities which will arise.
‘Despite these technical details being similar, [Hadid’s] concept and our design are completely different.’
Kuma, who said he did not enter the original competition for the stadium because its conditions insisted entrants must be Pritzker Prize-winners, was awarded the job following a relaunched contest.
He added: ‘If you take a look at the designs of Zaha Hadid and of myself you see very different impressions of the building. The reason for this is that in Hadid’s design you see the audience parts separated into two sides which rise up. But in our design we have very much tried to keep it as low as possible.
‘In regards to the actual structure of the stadium, our design utilises three layers; this ensures that at this scale we can still keep the audience and the athletes close.
‘When we looked at the 11 entries submitted to the competition originally, seven of them were using this three-layer design. It is the most reasonable way to ensure that in a stadium of this capacity the audience and athletes feel as one.
‘Zaha’s design also utilises these three layers within the stadium structure. When we look at sightlines and calculate the angles automatically it comes up with the most appropriate, so if we consider this then it is quite natural and appropriate that there are similar angles in Hadid’s design and my own.
He continued: ‘One further aspect which is similar is the details of the rows of seats. However, according to Tokyo’s fire prevention acts, this is very much set. Only certain layouts can be permitted within these limitations.’
Kuma on his stadium design
We have looked at utilising the green space and ensuring the stadium is in harmony with its surroundings.
In the planning of this stadium, we have ensured that the stadium stays at a low height. Its maximum height is 49m to ensure that it fits in with the surroundings. We have also tried to use natural materials as much as possible in the design – particularly wood.
Real plants will be planted within the stadium. These will all be indigenous plants local to Tokyo. This will ensure that the stadium remains in harmony with the green of the forest surrounding it.
In the process of planting so much greenery within the stadium I’m sure many people are concerned with maintenance. So in the planning process we have tried to utilise plants which need as little care as possible.
Usually in the process of architecture often it is created by looking at models from above. However, what we believe to be extremely important is to consider how things are from the human level. We wanted to make sure it is something which is friendly to humans and is user-friendly.
There are also many trees located within the eaves of the stadium. This is utilising one of the elements of traditional Japanese architecture in which amongst the traditional eaves of the building there are many trees planted. We have really tried to utilise traditional skills and wisdom as much as possible.
Using wood in the building’s eaves in this way also means the rain does not directly hit the wood. This way the wood can be very long-lasting. It is a way to ensure the building can be easy to maintain and also reduce maintenance costs as well.
The roof is a composite made of wood and steel but the way the design has been put together allows you to see just wood when you look up at the roof from below. So I very much hope or believe that when the audience enters the stadium and looks up they will feel surrounded by the wood and feel a sense of warmth and being at ease.
A glass roof encircles the open part of the dome and here there are solar panels. The solar panels will be fixed in a way that the audience can see them when looking up from their seats. This is very deliberate. We were looking to make this environmental technology very visible as part of the design. The electricity that will be generated through these solar panels fixed to the roof will be used for the water for the plants and greenery on the stadium.
Within the design we have very much tried to look at how we can utilise natural wind as much as possible so as not to use air conditioning. Using natural wind to ensure comfort in a building is also something which comes from traditional Japanese design and architecture. We are trying to revisit this and bring it to the stadium design in a contemporary fashion. For this aspect it is important to simulate and calculate the wind. What we are utilising here is in summer – when the Tokyo winds are generally from the south – we are making sure that the wind is coming down to the audience and acts in cooling fashion. In winter – when we have more northerly winds – it is problematic if this comes directly to the audience so the eaves design and the angles ensures that it winter the wind will go away from the seating.
With this design no matter where the member of the audience is seated they can feel close to the action.
Another characteristic of the design is what we are calling the ‘Grove of the Sky’. This will be open to the citizens of Tokyo at any time of the day. The walkway can be accessed directly from outside the stadium. The full circuit of this walkway is 850m so I imagine people running or going for jogs along it. This will be an area that the citizens of Tokyo can very much enjoy.
We are using Japanese cedar for the facades and Japanese larch for the roof areas. Wherever possible we are using traditional woods to look at how we can revive the natural forests in Japan. In the past 20 years there have been rapid technological evolutions in the ways to prevent wood from burning and decaying this has meant the wood can be used as a primary material in urban areas.