ZIN (Brussels) - an example of sustainable transformation applied to high-rise building

The “ZIN in No(o)rd” project revitalizes the iconic 1970s WTC I and II towers in Brussels, creating a dynamic hybrid structure that includes offices, housing, a hotel, sports facilities, shops, and green spaces. This flexible design sets a new European standard for large-scale mixed-use buildings. Central to the project is radical reuse, with 95% of materials repurposed, including 30,000 tonnes of concrete rubble recycled into certified aggregate, reintroduced into the construction process. Key structures, including the cores and basements are preserved. Structural engineering played a crucial role, overcoming challenges such as reinforcing deep foundations (55m), using post-tensioned structures to redistribute high loads and minimize foundation interventions, and adapting the cores to withstand increased wind loads. The project balances sustainability and modern requirements, demonstrating how adaptive reuse and innovative engineering can achieve a transformative and sustainable high-rise renovation.