The refurbishment of Liège’s Cité Administrative combines photovoltaics, geothermal energy, and an optimised envelope to achieve a near carbon-neutral building. It integrates digital management and passive solutions, proving that efficiency can be achieved without demolition.
The renovation of the Cité Administrative in Liège, an emblematic building from the 1960s, was conceived as a benchmark project in sustainability. The goal is to transform an energy-obsolete tower into a highly efficient, near-zero emission complex without resorting to demolition. This decision, besides preserving resources, significantly reduces the carbon footprint associated with construction.
The core of the energy strategy combines renewable production and passive optimisation. 1,600 m² of photovoltaic panels were installed on blind façades and the roof, even integrating artistic elements into the design. For climate control, the building uses shallow geothermal energy: four 15-metre wells in the bed of the River Meuse allow heat extraction in winter and cooling in summer, managed through water-to-water heat pumps and radiant ceiling systems. This solution eliminates gas dependency and ensures thermal autonomy.
The thermal envelope was reinforced with insulation on the gables and 5,000 m² of double-glazed joinery, adapted according to orientation. Added to this is a dual-flow mechanical ventilation system, which recovers energy and improves summer comfort. For lighting, an intelligent system with automatic regulation and presence sensors was implemented, reducing unnecessary consumption.
A notable feature is the centralised technical management (CTM), which integrates heating, ventilation, and lighting into a digital platform to optimise parameters in real time. This approach not only reduces losses but also facilitates maintenance and future adaptation.
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