ZIN in Noord stands as one of Europe’s most ambitious examples of adaptive high-rise transformation, redefining how existing towers can be reworked to meet contemporary urban, environmental, and social demands. Rising 111 metres in Brussels’ Northern Quarter, the project has been awarded “World’s Best High-Rise Building of 2025” by the Council on Vertical Urbanism (CVU), recognising its pioneering approach to reuse rather than replacement.

The project transforms two 1970s office towers into a unified mixed-use building, combining offices, residential units, and a hotel, supported by retail, sports facilities, and publicly accessible spaces. Instead of demolition, the design strategy prioritised structural retention, preserving approximately 85% of the original structural mass, including cores and foundations. This decision significantly reduced embodied carbon and construction waste, positioning ZIN as a benchmark for sustainable vertical redevelopment.

Designed by a multidisciplinary team led by 51N4E, Jaspers-Eyers Architects, and l’AUC, the project introduces a new architectural volume that interlocks the existing towers through a sequence of double-height floors, creating spatial continuity and a strong vertical identity. Programmes are distributed using a so-called “zebra” configuration, where offices, living spaces, and hotel functions alternate vertically, enabling the building to operate as a 24-hour urban ecosystem rather than a mono-functional tower.

The façade strategy plays a critical role in this transformation. High-performance envelope upgrades improve thermal efficiency while allowing daylight penetration deep into the floorplates. Terraces, winter gardens, and setbacks break down the building’s massing and introduce outdoor spaces at height, extending public life vertically through the tower. A public roof garden on the upper levels reinforces this ambition, offering shared green space within the dense city fabric.

By merging circular construction principles, mixed-use programming, and façade-driven performance, ZIN in No(o)rd demonstrates how existing high-rise structures can be reimagined as resilient, future-ready urban infrastructure, not as relics of the past, but as foundations for the next generation of cities.