Züblin Developing Timber Modular System at the Stuttgart University of Applied Sciences

Züblin’s timber modular construction system “Eco-Box” is under development in collaboration with the University of Applied Sciences in Stuttgart, Germany, Construction Briefing reported (9-2-24). In July, the company announced funding from the German government worth €718,000 (US$795,000) to help continue research and development.

The process applies a conventional modular approach while using traditional CLT, Züblin told Construction Briefing, “The timber construction system will be developed with the aim of combining a modular design with a decoupled, primary load-bearing system and was submitted to the ‘renewable raw materials’ funding program for further research.”

The company said the program, through the Ministry of Food and Agriculture’s Agency for Renewable Resources, will run for 36 months in total, which includes the construction of a demonstration unit using Eco-Box methods and materials.

“The demonstrator will be used to research and implement information on prefabrication and logistics, BIM, building physics investigations, and sustainable building service technologies in a total of five work packages,” said Züblin.

So, what sets the Züblin’s Eco-Box apart from other modular methods?

According to the company, “Our Timber construction system differs from other methods in that the prefabricated modules are not stacked on top of each other, as is usual in modular construction. The innovation of the Eco-Box based on the modular principle consists in the separation of the modular system into a primary and a secondary supporting structure.”

In other words, the CLT modular units are placed and fixed to a primary supporting structure as opposed to the units themselves, serving as primary supports. “This construction method means that special uses [like] double stories, loggias, etc. can be realized easily and cost-effectively,” Züblin said.

“The primary supporting structure forms a frame of reinforced concrete, [along with] the secondary supporting structure (the so-called ‘Eco-Boxes’). These are not stacked on top of each other but pushed into a stiffened shelving system like drawers. The boxes can be used individually for small apartments or combined for larger residential or office units.”

The boxes themselves aren’t entirely made from timber, either. Reinforced concrete floors accompany the CLT wall and ceiling elements.