Architecture is increasingly moving towards sustainable construction methods. An outstanding example of this is the CARL wooden high-rise in Pforzheim—a hybrid wooden structure that innovatively combines wood, concrete, and steel. With 14 floors and a height of 38 meters, CARL is one of the tallest wooden high-rises in Germany and offers over 5,000 m² of living space.
Wood as a central element
Wood is the main structural material used in the building and also characterizes the façade. As a renewable raw material with high load-bearing capacity, low weight, and good insulating properties, wood is not only ecologically sound, but also functional. It stores CO₂, creates a pleasant indoor climate, and meets high fire safety requirements—thanks to predictable burn rates and pollutant-free construction. The high degree of prefabrication of the wooden elements also significantly accelerated the construction process.
Structural concept: Skeleton construction with hybrid structure
The building is based on a skeleton construction with load-bearing facade supports and ring anchors. The ceilings span from the exterior walls to the central stairwell core. Where direct supports are lacking, Peikko's DELTABEAM® composite beams are used. These enable slim wood-concrete composite ceilings with large spans and high load-bearing capacity – ideal for flexible floor plans and open living concepts.
DELTABEAM®: Key technology for timber high-rise construction
DELTABEAM® composite beams combine the advantages of steel and concrete and can be seamlessly integrated into timber structures. Their prefabricated connection details facilitate assembly and reduce construction costs. Thanks to integrated reinforcement, they also offer effective fire protection without additional cladding. The slim ceilings contribute to energy efficiency as they require less building envelope and reduce heating and cooling requirements.
Efficient operation
CARL demonstrates how modern construction can combine ecological responsibility and creative freedom. As a KfW Efficiency House 55 EE, it requires only 55% of the energy of a comparable conventional building. The combination of timber construction and innovative structural design sets new standards for urban residential construction.
