Spanish architectural studio Temperaturas Extremas has designed a bird and mammal refuge and water reservoir in a protected forest in the “Plateau Kirchberg” quarter in north-eastern Luxembourg City. The studio’s challenge was to integrate the 50-meter-high structure with a 1,000-cubic-meter drinking water reservoir into the site’s sensitive context.
The Luxembourg forest is listed as a Natura 2000 site, a network of more than 27,000 nature protection sites that extend across the 27 EU Member States. A study of the forest’s conditions and its relation to other Natura 2000 sites led Temperaturas Extremas to conceive a program that meets the needs of local birds, bats, and migrating species. The water reservoir functions as “just another tree on the site,” says the studio.
A project for Luxembourg City’s Water Department, Temperaturas Extremas designed the program as two volumes, thereby reducing the water tower’s impact on the forest site — each volume has a cylindrical tank raised off the ground with a capacity of 400 cubic meters and 600 cubic meters respectively. The first volume consists of a rough, prefabricated concrete skin with swallow nests placed at varying heights and precise orientations; this volume also includes a nest for peregrine falcons, built at a height of 50 meters. Temperaturas Extremas worked in collaboration with teams of naturalists and ornithologists to select the materials and study the most advantageous positions for each nest.
The second volume is clad in cork, a material that acts as a natural thermal insulation layer against the water tank. A second permeable skin of untreated larch wood slats surrounds this cork layer, adding a visual contrast to the adjacent volume’s concrete skin. This wooden skin is designed to encourage the nesting of seasonal birds and also incorporates bat roosts. In time, the wooden skin will be covered with vegetation, providing camouflage and ensuring the structure stands in harmony with and adds to the local ecosystem.
A permeable metal skin protects the ground floor, deterring intruders; the ground-floor roof has a vegetative cover that extends the forest floor. Temperaturas Extremas used rammed earth for the exterior and interior paving in this area.
The water tower includes rainwater collection systems, an observation deck, and a series of walkways that facilitate servicing and the monitoring of nests.
