Dezeen Magazine

Kazuko Akamatsu outlines Shibuya skyscraper design in video by CCA

In the second Models Talk film published in collaboration with the Canadian Centre for Architecture, Japanese architect Kazuko Akamatsu explains how she used voids to create a feeling of openness at the Shibuya Stream skyscraper in Japan.

The nine-minute video, aptly named A Matter of Void, takes viewers through the design process of creating the 37-storey skyscraper and retail complex in Shibuya, Tokyo.

Snippets of a scaled model are woven in between video footage of the finished building, as a voiceover by Akamatsu sheds light on how it is designed to connect visitors to the outside.

Architectural model of Shibuya Stream in Tokyo
Shibuya Stream in Tokyo is the focus of the film A Matter of Void

A Matter of Void is one of three videos being published this week by the research institution and museum Canadian Centre for Architecture (CCA) in partnership with Dezeen.

The film series, named Models Talk, explores recent architecture projects in Japan that address different urban issues. Each video is available to watch in Japanese with English subtitles.

The first video, published yesterday, saw architect Erika Nakagawa share her vision for a skinny residential tower on a small and dense site in Tokyo.

An architectural model of Shibuya Stream in Tokyo
Kazuko Akamatsu discusses the skyscraper's design in the film with a scaled model

Shibuya Stream was developed by Akamatsu as part of Coelacanth and Associates, an architecture studio where she is a partner. In A Matter of Void, she focuses specifically on the design of the building's lower levels, which are punctured by a series of voids.

The architect said these voids create a feeling of porosity and help visitors to connect to the outside, deliberately challenging more traditional skyscrapers that are designed as sealed-off environments.

"When you enter a typical high-rise building, you are completely enclosed by interior air," Akamatsu explained.

"But here, we wanted users to see the outside," she continued, "to feel what's happening outside by interacting with the outdoor air."

The voids that break up the Shibuya Stream serve primarily as semi-outdoor terraces. However, one of the largest ones incorporates a big open staircase.

Pointing at the scaled model in the video, Akamatsu explained how this stairway was designed to draw people up from the street and open up the building to the city.

Other voids in the building help bring in natural light, while others simply serve as visual links throughout the development.

"It's nice to have visual contacts with various scenes in the building even if you cannot be there," said Akamatsu. "This is the condition we wanted to create."

An architectural model of Shibuya Stream in Tokyo
The video highlights the tower's large staircase

As part of the film, Akamatsu also uses the scaled model of Shibuya Stream to highlight the curved passage that runs through its ground floor.

This passage, which was modelled on an old train line that previously occupied the site, informed the zoning of the building's lower levels. Shops and restaurants are left open to the passage and encouraged to spill out onto it, while terraces on the upper floors look down onto it.

Akamatsu graduated from Japan Women's University in 1990, before joining Coelacanth and Associates and being promoted to partner in 2002.

Alongside practising as an architect, she is also a professor at Hosei University and lecturer at Kobe Design University.

Glass facade of the Shibuya Stream skyscraper in Japan
Footage of the finished building is woven into the film

The three-part Models Talk series was produced by the CCA in collaboration with architectural curator Kayoko Ota and directed by architectural design firm Studio Gross.

It was carried out for the CCA c/o Tokyo programme, which is run by the institution with Ota to "develop research and projects, and to facilitate public engagement in Tokyo".

On 8 December, the CCA will be hosting a live conversation at 8:00pm Montreal time with its director Giovanna Borasi, alongside Ota, Studio Gross and the architects featured in Model Talks. The panel will discuss the film series and the urban issues they address.

Attendance is free and registration is open here. To find out more about CCA c/o Tokyo, visit

Partnership content

This article was written by Dezeen for CCA as part of a partnership. Find out more about Dezeen partnership content here.