Renowned architect and Junya Ishigami+Associates founder, Junya Ishigami designed a multipurpose semi-covered plaza for the students of the Kanagawa Institute of Technology in Japan. Featuring rectangular roof openings, the plaza is unusually designed for the ceiling and ground to bend and meet at a distance, much like the horizon on the landscape.

Situated adjacent to the award-winning KAIT Workshop building, also designed by Ishigami in 2008, the plaza was conceptualised to provide a semi-outdoor breakout space for the students of the institute.

Most of the outdoor spaces on the campus were surrounded by school buildings; landscape diversity that would have otherwise resulted in a constantly changing natural environment was missing, lending a certain artificiality to the surroundings.

According to Ishigami, the campus lacked places where students could take a break and relax, sit on the ground enjoying lunch, take a nap, and even do sports training on rainy days.

Two primary factors influenced the design of the plaza – versatility and semi-outdoor – with the design intent focussing more on the experience of the space rather than the ways to use it.

“It is such a place where the centre of gravity is more about ‘how to spend’ than ‘how to use’,” says Ishigami about the semi-outdoor plaza.

This necessitated the design of an attractive heterogeneous space that would have multiple potential uses from everyday social interactions to hosting campus festivals.  

Ishigami’s design capitalises on the two-metre height difference between the campus ground level and the project plane, with the building height minimised to create a new ground space that is integrated with the natural ground.

The architect describes the design as a structure that is “imagined from the action of lifting up an expansive iron plate on four supporting walls. Without any column inside, the iron plate bends slightly to form a spectacular curved surface”. The ground is also concave, in alignment with the smoothly curved ceiling.

“By referencing the proportion in section between the sky and earth, the height of the ceiling is set as low as possible in relation to the vast plane of the space. The ceiling and the ground bend and stretch to meet in the distance, thus creating a horizon inside the building,” Ishigami explained.

The roof has 59 rectangular openings that bring natural light into the space below, with the intensity of the light changing along the path of the curved ceiling. The openings have been left uncovered to allow wind and rain inside. People can sit on the sloped floor, stand or even lie down within the space, without feeling confined while being connected to the building and the environment as part of an immersive experience.

The plaza has two entrances to the open semi-covered space, uninterrupted by any structural supports. The building covers an area of more than 4100 square metres, with a maximum roof span of 90 metres and a ground slope of 5 metres from one end to the other. The 12mm steel plate forming the roof is supported by 250mm thick walls while 83 piles and 54 ground anchors make up the huge concrete foundation beam. A network of ribs installed as compression rings reduces the tension on the external walls. Water permeable asphalt covers the ground to absorb the rainwater instantly, helping keep the space dry.

“The relationship between people and environment should be as close as possible, in a direct relationship, so they can feel the nature strongly when sitting on the ground, and develop an intimacy with the building when sitting on the floor,” Ishigami said.

Photos: Junya Ishigami + Associates.