When we talk about sustainability in construction, the Belgian Pavilion at Expo 2025 Osaka is more than just an eye-catching building. It is a real-life experiment in how to design, measure, and rethink what “building responsibly” means on a global stage.
Why construction matters
Construction is one of Belgium’s most important economic sectors. But it also accounts for around 40% of the country’s total energy consumption, generates large amounts of waste, and uses huge volumes of raw materials. Reducing this impact is crucial if Belgium is to meet its climate commitments: cutting greenhouse gas emissions by 50% by 2035 and reaching climate neutrality by 2050.
To achieve this, Belgium has developed a set of tools and methods that go beyond international standards and are applied across the three regions of the country. These include:
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PEB – measuring energy performance in buildings
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TOTEM – assessing the environmental impact of construction materials over their full life cycle
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GRO – a framework inspired by international ISO standards to evaluate large projects in a holistic way
These systems don’t just help build greener. They make sustainability measurable and transparent.
The Pavilion as a test case
The Belgian Pavilion at Expo 2025 Osaka puts these methods into practice. Designing a temporary building 9,300 km away from Brussels, under strict Japanese building codes (including earthquake resistance), and with the ambition of giving it a second life after the Expo, posed extraordinary challenges.
To answer them, the project team used a double life cycle analysis (LCA): one based on Belgian data (TOTEM) and another adapted to Japanese materials and conditions. This helped estimate not only the carbon footprint of the one-year Expo, but also a projected 50-year second life.
Transport paradoxes and smart choices
At first glance, shipping Belgian materials like the famous blue stone from Soignies to Japan might seem contradictory to sustainability goals. But the analysis revealed an interesting paradox:
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Maritime shipping is far more energy-efficient than road transport.
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Studies show that transporting materials by ship represents only about 10% of their total life-cycle energy use.
This means that using high-quality, durable Belgian materials, even if shipped overseas, can still fit into a responsible approach, especially when combined with local Japanese resources for the structural core of the building.
Human and organisational challenges
Beyond the technical side, building the Pavilion was also a human adventure:
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Managing a construction site from Belgium using digital BIM tools
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Coordinating Belgian and Japanese teams under very tight deadlines
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Adapting continuously to logistical and regulatory hurdles
All of this required creativity, flexibility, and collaboration across borders.
A temporary building designed to last
Although the Pavilion is, by definition, a temporary structure, it has been designed from the start for a second life. Its modularity and dismantlable design reflect Belgium’s commitment to a circular economy, where buildings are not disposable but adaptable and reusable.
More than architecture
The Belgian Pavilion at Expo 2025 is therefore not just a place to discover Belgian innovation and creativity. It is also a showcase of sustainable construction, questioning how we build, transport, and use our resources — and offering lessons that go far beyond the Expo.
When you step inside, you will not only experience the imagination of Carré 7’s architects and the scenography of the exhibition, but also the deeper reflection on how to build a future that is both beautiful and sustainable.
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