Bird and Mammal Shelter and Water Reservoir

Set in a protected Natura 2000 forest in Kirchberg, Luxembourg, the project transforms a utilitarian water reservoir into a living architectural organism. Two cylindrical volumes contain 1,000 m³ of drinking water while hosting habitats for birds, bats and seasonal species. Prefabricated concrete, cork insulation and untreated larch define a material language that blends into the woodland. Acting as both infrastructure and ecosystem, the structure embodies coexistence between technology, nature and architecture.

The principal challenge was integrating a 50 m-high technical reservoir into a fragile forest without disrupting ecological cycles. Following ecological surveys and consultations with ornithologists and naturalists, the strategy prioritised a low visual profile, habitat provision and reversibility. The programme is divided into two volumes: a prefabricated concrete volume that integrates swallows' nests and a peregrine falcon ledge, and a cork-insulated volume wrapped in untreated larch designed to host seasonal species and bat roosts. This separation allows strict technical performance, including water containment and maintenance access, while generating new habitats and strengthening landscape connectivity.

Materials prioritise low embodied carbon, local sourcing and reversibility. Prefabricated rough concrete forms the primary tank envelope; cork provides sustainable external thermal insulation; and untreated larch boards are fixed to a bolted ventilated subframe that will support vegetation colonisation. The ground floor uses rammed earth paving and a permeable metal skin for controlled access. Structural logic favours prefabrication and bolted assembly to reduce on-site works and enable disassembly. Operational sustainability is achieved through passive thermal strategies and remote monitoring of hydraulic systems, lowering energy and maintenance costs. Maintenance recommendations include periodic inspection of timber elements, vegetation management to avoid undue loads, scheduled checks of bolted connections and remote sensor calibration to ensure habitat continuity and façade performance. Specialists should check on nests in ordr to track the bird and mammal population.