Material Flows / Building within Planetary Boundaries

International Symposium / Exhibition | Scales and Practices of Sustainable Development

  • Language German / Japanese
  • Price
    Symposium: free, registration required
    Exhibition: free

Material Flow quadratisch ©Hiroshi Toyama

Material Frows ©Hiroshi Toyama

‘Material Flows / Building within planetary boundaries - Scales and Practices of Sustainable Development‘ is part of the bilateral cultural programmes of the Goethe-Institut and the Institut Français as part of Expo Osaka 2025. In cooperation with partner institutions and universities from Japan, Germany and France, new impulses are being set for sustainable construction.
The exhibition and symposium engage with material cycles, recycling, insulation, energy efficiency, and experimental approaches to circular construction, highlighting innovative practices in the use of resources across diverse building cultures. The project investigates how architectural sustainability can be conceptualized and conveyed as an ecological, technical, cultural, and social phenomenon—highlighting the full life cycle of buildings, their transformation over time, and the social networks that drive and sustain environmentally responsible construction practices. The project is supported by the Franco-German Cultural Fond.

EXHIBITION “Material Flows”


Date: 26 April – 30 June, 2025

Venue: The local culture center, Chidori Bunka

Entry fee: Not required


Material Flows explores the trajectories of building materials – from extraction and processing to use, deconstruction, and reuse. The exhibition investigates how material flows can be optimized to reduce environmental impact while responding to the needs of future building cultures. It presents recent research, newly developed components made from recycled or organic matter, and experimental approaches to circular architecture.

The exhibition is structured around three themes: new material properties emerging from molecular reconfiguration, resource-efficient construction using low-energy materials, and strategies for recycling and reuse.
The exhibition builds on the “Pop-Up Campus” in Aachen (2022) and brings together international contributions from Germany, France, Japan, Belgium, and the Netherlands. Accompanying the exhibition are school workshops and guided tours through the transforming district of Kita-Kagaya.

Curators: Prof. Axel Sowa, Dr. Murielle Hladik  
with Marius Helten, Saori Toyoshima (Spatial Design), Frédéric Schnee (Editing)  

The symposium, the exhibition and its side program have been initiated by Professor Axel SOWA and Dr. Murielle HLADIK, Chair of architectural theory at RWTH Aachen University.

SYMPOSIUM “Building within Planetary Boundaries – Scales and Practices of Sustainable Development” (Past Event)

Date: 23-26 April, 2025
Venue: Umeda South Hall, Osaka (on 23 April), The University of Osaka Nakanoshima Center (on 25-26 April)
Entry fee: free (Registration required)

The international symposium brings together architects, urban planners, researchers, and representatives of public institutions from Germany, France, and Japan to discuss scales and practices applicable in different building cultures. Key topics include the decarbonisation of the building stock, material cycles, reuse, life cycle assessment, as well as social participation, urban ecology, and climate-neutral architecture.

The program features expert lectures, panel discussions, a guided visit to Expo Osaka 2025, and keynote speeches by Prof. Thomas Auer (Technical University of Munich), Prof. Sébastien Marot (ENSA Paris-Est), and Louisa Hutton (Sauerbruch Hutton, Berlin), among others.

The symposium will conclude on 26 April with the opening of the exhibition Material Flows at Chidori Bunka, a cultural venue located in Osaka’s Kita-Kagaya district.

Days 1 (23 April), 3 (25 April), and 4 (26 April) are open to the general public upon prior registration. Day 2 (24 April), organized by RWTH Aachen and BBSR, will serve as a networking day for invited delegates and speakers of the symposium.

Registration symposium

Further information 


EXHIBITION: Material Flows
Organisation: RWTH Aachen University, Chair of Architectural Theory
Support: Program ”Zukunft Bau” of the Federal Institute for Research on Buildings, Urban Affairs and Spatial Development (BBSR, Germany) / Fond Culturel Franco-Allemand, Deutsch-Französischer Kulturfonds (France-Germany) / Goethe-Institut Tokyo / Institut français du Japon
Special thanks: Chidori Bunka, Chishima Real Estate Co., Ltd., Osaka

SYMPOSIUM: Building within Planetary Boundaries – Scales and Practices of Sustainable Development 
Organisation: RWTH Aachen University, Chair of Architectural Theory / The University of Osaka (Japan) / German Centre for Research and Innovation Tokyo (DWIH Tokyo) / Federal Institute for Research on Buildings, Urban Affairs and Spatial Development (BBSR, Germany) / Building Research Institute (BRI, Japan) / National Institute for Land and Infrastructure Management (NILIM, Japan) / Öko Zentrum NRW (Germany) / Institute of Science Tokyo
Support: Takenaka Europe / IF-Export (Institut Français, Paris, France) / Ambassade de France / Goethe-Institut Tokyo