Membrane roofs are used on the pedestrian deck of the OIMACHI TRACKS, which opens on March 28.

(Tokyo headquarters: Setagaya-ku, Tokyo; Osaka headquarters: Yodogawa-ku, Osaka; President: Yumi Nomura), a company involved in large-scale membrane surface structures (tent structures) and civil engineering and logistics materials, has taken charge of the construction of a membrane roof for the OIMACHI TRACKS complex in front of Oimachi Station, which will open on March 28, 2026, The company was in charge of the construction of the membrane roof of the pedestrian deck.

OIMACHI TRACKS is a complex facility developed by East Japan Railway Company in the Hiromachi district around Oimachi Station that includes offices, a hotel, commercial facilities, and residences. The opening of the new complex is expected to improve circulation and create a lively atmosphere around Oimachi Station.
We have installed a membrane roof on the pedestrian deck that connects to the traffic plaza, creating a comfortable environment that is less affected by weather conditions. The membrane roof has a surface area of approximately 446 ㎡, and its translucent membrane material allows natural light to softly enter, creating a bright and open urban space.

The translucency of the membrane material allows natural light to softly enter the room, creating a bright and open space. Furthermore, the titanium dioxide ^{photocatalyst*1} coating on the membrane material breaks down organic matter that causes stains. Rainwater washes away the dirt, creating a self-cleaning effect that maintains a beautiful white appearance over the long term. In addition, the roof design harmonizes with urban space by taking advantage of the features of the membrane structure, which is lightweight and can achieve large spans (a structure with a wide sense of columns). This contributes to the creation of spaces where people can stay and interact with ease.

The membrane is placed under the steel frame to reduce visual noise in the pedestrian’s view and create a clean, continuous ceiling surface. Furthermore, the combination of four inverted pyramid shapes creates a three-dimensional expression and contributes to securing the drainage slope, thereby achieving both design and functionality.

The white membrane roof is coated with an ethylene tetrafluoride resin coating membrane (PTFE membrane) ^*2. The titanium oxide photocatalyst on the surface decomposes organic dirt, which is then washed away by rainwater, thus maintaining the white appearance for a long period of time.

*1 Titanium dioxide photocatalyst: It absorbs sunlight (ultraviolet rays) to oxidize and decompose organic matter, and therefore, when sunlight hits the titanium dioxide photocatalyst membrane material, it decomposes organic stains.

*2 Tetrafluoroethylene resin coated membrane (PTFE membrane): A strong composite material made of glass fiber fabric coated with fluorocarbon resin, which is also used in the world’s first permanent membrane structure building, the University of La Verne Sports Science and Athletic Pavilion (constructed in 1973, California, USA). It has been used for over 50 years without significant functional or performance problems.

We have a large number of achievements in the field of underlayment membranes, and some representative examples are introduced below.

Umekita Green Place
https://www.taiyokogyo.co.jp/news/66545/ (our press release)

・Yaesu Grand Roof
https://www.taiyokogyo.co.jp/works/8670/ (our results page)

Address: 2-1-3, Hiromachi, Shinagawa-ku, Tokyo 140-0005, Japan 2-1-3 Other Addresses

Access: JR Keihin Tohoku Line Tokyu Oimachi Line and Tokyo Waterfront Area Rapid Transit Rinkai Line “Oimachi” station

Scale: 26 above ground, 3 basement levels, approx. 250,000 m2 (A-1 district), 2 above ground, 2 basement levels, approx. 9,100 m2 (A-2 district)

Number of stores: approx. 80

Opening date: March 28, 2026

Owner: East Japan Railway Company

Designed by JR East Architects & Engineers, Inc.

Construction: Takenaka Corporation

Membrane construction: January 2024 January – January 2026

Taiyo Kogyo’s scope of work: design, manufacture and installation of membranes

Membrane material: AP450

Membrane surface area: 446 m2

Taiyo Kogyo has been a leading manufacturer of large membrane structures for over 100 years, and was the first in the world to realize a low-rise (reduced height) pneumatic membrane structure for the U.S. Pavilion at the 1970 World Exposition in Japan, where the roof was supported solely by air pressure. Since then, we have also constructed the membrane roof of the Tokyo Dome and the Millennium Dome (now the O2 Arena) in London, one of the world’s largest dome facilities: The O2 Arena (now The O2 Arena) in London, the world’s largest dome facility, and other large-scale projects around the world. In addition, we designed and constructed more than 20 pavilions for the Osaka-Kansai Expo in 2025, supporting the creation of the Expo venue. With membrane structure technology that excels in economy, workability, translucency, and design at its core, TSP Taiyo has developed its business in the construction of sports and transportation facilities, as well as in the civil engineering, logistics, and environmental fields, supporting the safety and security of society.

Together with group companies such as TSP Taiyo Corporation, which provides event consulting services, and ACTIO Corporation, which manages facilities, we are committed to “Making the world softer and the future warmer. Warming the future. We will continue to provide new value to society under the slogan “Make the world softer and the future warmer.