PROJECT DETAILS
Flagship Circular Project – Timber-Hybrid Building “The Cradle” Equipped with Sustainable Window and Façade Systems from WICONA
With “The Cradle,” a pioneering project for digital planning and circular construction has been realized in Düsseldorf according to plans by HPP Architects. The office building, constructed using a timber-hybrid method, impresses with its holistic overall concept and follows the Cradle-to-Cradle principle. Façade elements incorporate aluminum systems from WICONA made from the CO₂-reduced aluminum alloy Hydro CIRCAL 75R.
Located in the trendy MedienHafen district of Düsseldorf, “The Cradle” was built on a site directly along the Rhine and offers a total of 6,600 m² of office space as well as high-quality gastronomy on the ground floor. The goal of the Interboden Group (Ratingen), as the investor, was above all to create a flagship project for the future of building—featuring striking architecture and consistent sustainability in line with the Cradle-to-Cradle principle (“from cradle to cradle”). This means that thinking in life cycles was a priority right from the start—particularly regarding the materials used. The building itself is conceived as a materials warehouse for the future. All construction materials were selected and installed based on their material health, purity, and separability, ensuring they can be reused or reintegrated into the material cycle at the end of their life. The integral planning also includes an energy concept with renewable energy generation through both photovoltaic and geothermal systems.
Sustainable Building Concept and Project-Specific Façade
“The Cradle” was realized entirely using prefabricated elements. Except for the basement, ground floor, and load-bearing core, the key components were constructed from renewable timber. The rhombus-shaped structure of glass and wood combines the façade and load-bearing framework, developed by HPP Architects in consideration of the local context and neighboring buildings. Designed parametrically in 3D, the external structural frame also provides shading, depending on orientation, thanks to its depth. An additional benefit of the varying depths of the framework and façade is the creation of usable loggias on the side facing the harbor basin. Equipped with fall protection, they offer an excellent view.
Sustainable Aluminum Systems on the Façade
While the ground floor features a timber mullion-transom façade with a 50 mm face width, the five upper standard floors utilize an aluminum ribbon window façade. The project-specific windows (1.25 x 3 m) are based on WICONA’s WICLINE Evo 75 system and are partly fixed glazing and partly operable. Barrier-free window doors were also integrated into the window ribbons. Internally, a matching sunshade system was installed. A special challenge was designing impact panes tailored to the rhombus or triangular shape of the façade structure. WICONA project manager Thomas Staiger explains: “We developed the suspended triangular-glass impact panel system according to the architects’ specifications, in collaboration with façade construction experts from Rupert App, and adapted it to meet structural requirements.” The top floor uses a project-specific mullion-transom façade of the WICTEC 50 type. All elements were made from the sustainable Hydro CIRCAL 75R aluminum alloy, which consists of at least 75% recycled end-of-life aluminum—scrap that has already gone through a complete life cycle in a previous product. Thomas Staiger: “Because Hydro CIRCAL 75R has a CO₂ footprint of only 1.9 kg CO₂/kg of aluminum, the product perfectly met the project’s high standards in terms of circularity and sustainability.”
Smart Integration of Cradle-to-Cradle and BIM
“The Cradle” also sets new standards in terms of integrated planning. All planning steps were carried out in BIM, and coordination between trades was managed using a 3D BIM model created in Revit. To combine the Cradle-to-Cradle concept with the BIM process, all materials used in “The Cradle” were documented in a “Building Material Passport.” This allowed for optimized material selection regarding recyclability and CO₂ footprint and also provides a comprehensive material inventory for future dismantling.
Sustainability Thought Through Holistically
The holistic sustainability approach of “The Cradle” is also backed by figures. A life cycle analysis assessed the building’s environmental impact. The result: the sum of all implemented measures leads to a CO₂ footprint (GWP) of only 41.17 kg CO₂/m² of net floor area over a 50-year usage period. A true flagship project for circular construction.
