Western and japanese concepts of spatial definition and materiality merge in a newly opened spa and health club in Tokyo, designed by COE architecture International.

Aqua Sports & Spa, which was completed this month for fitness operator Seta Sports Connection, is a six-storey, 6,000sq m (65,000sq ft) building in Setagaya-Ku ward. It replaces a 1980s facility, and has been designed to promote personal sports training, Japanese bathing and social activities “within a sophisticated environment equal to a five-star hotel.”

Fitness facilities include the only private 50-metre swimming pool in greater Tokyo, a gym, a spa lounge and traditional Japanese baths fed by onsen spring wells. Social elements include a lounge, bar, dining room and cafe with outdoor terrace.

Sports and social spaces are divided into white and dark grey concrete volumes, which vary in scale related to their function to bridge the wide gap between a utilitarian fitness club and a luxurious hotel.

“We know there's a big expectation of newness and hospitality in Japan," studio founder Christopher Coe told CLAD. "When you’re in Tokyo in particular, the buildings that are most attractive to people are wonderful hotels and shopping centres because of the out-of-home experiences they offer. We wanted to create that feeling. This is not just a sports centre, and it's not just a cafe. It’s an opportunity to consolidate all those interesting social space together.”

The architects included many windows and used semi-transparent and welcoming materials for the building’s exteriors to create "a public presence" in response to the project’s dense urban site.

"An important component of our design was to bring bathing out into the open, so we raised the pool in the air to make it visible through the building from street level," said Coe. “Japan has a very big bathing culture which is almost religious. Bathing is usually such a private thing, it's not about putting yourself on display. We wanted to invert that idea. It was a fantastic opportunity to blur the lines between the public and the private, and bathing and sport, to create something completely different.”