Timber facade for a Building Class 5 project with integrated vertical greenery
The TecHHub Hamburg in Science City Altona demonstrates how high design ambitions can be successfully combined with complex building regulations. The facade is made of Kebony Character and meets the requirements for fire safety, durability and ease of maintenance in Building Class 5.
Planning and Challenges
The new building for start-ups in the field of digital technologies was constructed using modular building methods. With a building height of more than 13 metres and usage units exceeding 400 square metres, the project falls into Building Class 5. The facade design therefore had to meet strict fire safety requirements. At the same time, vertical profile installation and an integrated three-sided facade greening system were required.
The German Model Timber Construction Guideline limits the ventilation cavity to a maximum of 50 millimetres. Under these conditions, conventional timber substructures with double cross battens could not be implemented in compliance with standards.
Structure and Solution
The planners opted for a metal substructure in accordance with DIN 18516 and guideline PA 07. Stainless steel brackets with thermal break elements were mounted onto the steel frame structure clad with non-combustible gypsum fibre boards. Horizontally installed aluminium angle profiles were used as supporting rails.
This construction ensures the required ventilation cavity of 50 millimetres. Local reductions, for example to compensate for tolerances, were permitted in accordance with standards. The facade profiles were fixed using stainless steel screws with a general building authority test certificate.
Facade Material and Maintenance
Kebony Character was used as a shiplap profile with dimensions of 21 × 148 millimetres. The two-stage modified wood meets the requirements of the German Model Timber Construction Guideline and features increased density. The selected profile type allows individual boards to be replaced without damage. This is a particular advantage in the public ground-floor area, for example in cases of vandalism or subsequent installations.
Fire Safety and Greening
Structural fire protection was achieved by steel sheets at internal and external corners and by compartmentalisation of the ventilation cavity. The facade greening system is designed as a separate steel cable system with its own foundations. A distance of approximately 30 centimetres from the timber facade ensures that vegetation and fire protection components do not come into contact. Automatic irrigation prevents the formation of dry plant material.
Durability and Base Detail
Kebony Character achieves durability class 1 to 2 and is suitable for permanently exposed facades with greening. The surface weathers evenly without treatment. A gravel strip at the base protects the facade from moisture and complies with Use Class 3.2.
Project Data at a Glance
Project: TecHHub Hamburg, Science City Altona
Facade material: Kebony Character, shiplap profile 21 × 148 mm
Installation: Vertical on aluminium substructure
Substructure: Aluminium angle profiles 40 × 40 mm in accordance with DIN 18516
Fixing: Stainless steel screws with general building authority approval
Ventilation cavity: Maximum 50 mm in accordance with the Model Timber Construction Guideline
Fire safety: Building Class 5 with steel sheets and cavity compartmentalisation
Greening: Steel cable system with automatic irrigation
