A model of the Z眉blin Eco-Box modular construction system using cross-laminated timber. (Image: Strabag)

Called the 鈥楨co-Box鈥�, Z眉blin鈥檚 timber modular construction system is under development in collaboration with the University of Applied Sciences in Stuttgart, Germany.

In July, the company announced funding from the German government worth 鈧�718,000 (US$784,042) to help continue research and development.

The process applies a conventional modular approach while using traditional CLT. Z眉blin told Construction Briefing, 鈥淭he 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 鈥楻enewable raw materials鈥� funding program for further research.鈥�

The company said the programme, through the Ministry of Food and Agriculture鈥檚 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.

鈥淭he 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,鈥� said Z眉blin.

Ultimately, the developing method is meant to deliver a new product while analysing sustainability gains, said the firm.

鈥淸Eco-Box] should allow for architectural diversity and variability, taking into account the location factors as well as the building鈥檚 internal structure.

鈥淚n addition, sustainability aspects are taken into account in the use of materials and in the construction process,鈥� said Z眉blin.

What鈥檚 sets Z眉blin鈥檚 Eco-Box apart from other modular methods?

A render of a Z眉blin Eco-Box structure. (Image: Strabag)

鈥淥ur 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,鈥� Z眉blin explained to Construction Briefing.

鈥淭he 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.鈥�

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.

鈥淭his construction method means that special uses [like] double storeys, loggias, etc. can be realised easily and cost-effectively,鈥� Z眉blin said. 

The company added, 鈥淭he primary supporting structure forms a frame of reinforced concrete, [along with] the secondary supporting structure (the so-called 鈥楨co-Boxes鈥�).

鈥淭hese 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.鈥�

The boxes, themselves, aren鈥檛 entirely made from timber, either. Reinforced concrete floors accompany the CLT wall and ceiling elements.

Is Z眉blin鈥檚 Eco-Box process more sustainable?

The Eco-Box is still firmly in the prototype phase, however, Z眉blin said that it has seen early positive returns on sustainability goals, particularly the reduced time and materials needed to produce an Eco-Box project.

For now, and as the process progresses, the development team is working out holistic solutions for high-level problems.

鈥淲e see the development of optimal, recyclable design solutions in combination with a recyclable overall process, from production and construction to operation and dismantling, as the greatest challenges,鈥� said Z眉blin, adding 鈥渋ssues relating to noise and moisture protection and the use of sustainable building technology systems are the top priority.鈥�

The company also revealed that demand, too, is a current hinderance, 鈥渄ue to the almost complete standstill of the residential construction market.鈥�

Strabag, Z眉blin and Unversity of Applied Sciences staff with Cem 脰zdemir, Federal Minister of Food and Agriculture, pictured second from right. (Image: Strabag)

But if builders can get back to building, the company believes Eco-Box can help deliver Germany鈥檚 nationwide sustainability goals (it aims to make the country鈥檚 building stock carbon-neutral by 2050).

鈥淲hen using wood, a very high degree of prefabrication can be achieved with great manufacturing accuracy. In addition, the transport weights are still easy to handle,鈥� said Z眉blin. 鈥淔urthermore, once the research work has been completed, the system should be recyclable, [and] the materials should be almost completely recyclable by type.鈥�

So Eco-Box may not yet be the modular method to disrupt the German built environment, but Z眉blin鈥檚 early research suggests the process could be beneficial, particular to regions short on residential home builds and the materials needed to produce cement and concrete.

Z眉blin board member Markus Landgraf added, 鈥淒ue to the great influence of the construction industry on global energy and resource consumption, it is essential to align our actions with the sustainability strategy when planning, building, renovating and operating buildings.鈥�