timber building system

Timber Building System

Computational Design and Digital Fabrication



Collectively, the entire ITECH class of 2021 worked together to design and fabricate a novel timber building system. The construction industry is trending towards more timber usage; it is an environmentally sustainable material that is renewable and sequesters carbon from the atmosphere. Further, heavy timber is a fire safe material. However, timber is typically employed in very rigid grids that span in one principal direction. This makes for a limited architectural expression that is not as freeform as other materialities such as concrete. The aim of this collaborative effort was to employ timber in a way that allows for more design freedom, particularly in the column layout. The proposed system is a type of layered floor panel with CLT plates on the outsides sandwiching timber webs within. Through computational design and digital fabrication, the system can have a local response to the dynamic conditions, and achieve all the metrics of success.

x-ray timber building


Digital Fabrication System

This dynamic timber building system is only possible with highly tailored components that are made for their specific use case. To achieve this, the team neaded to devise a manufacturing methodology that could be efficient and flexible. To sastisfy all the metrics of success, the system needs a high degree of automation.

Ultimately, the ITECH studio designed an assembly line composed of two anthropomorphic robots and a moving linear table. The two anthropomorphic Kuka robots work in parallel to place and glue the various timber components. The linear table can move the sandwich panel to give the robots a greater reach. Further, the linear table is designed to take a vacuum bag to apply pressure for the glued components. Thus, the ITECH studio designed a compact manufacturing facility that can be transported on a single truck bed.

modular construction system


Modular Construction System

The ouput of the fabrication system is modular sandwich panels that are 3.2m max width. This is such that the panels can be transported using standard trucks. While this provides manufacturing and transportation efficiency, this does present the challenge of connecting the panels on site. Compounding this, the system was designed to have similar design flexibilities that are found in concrete. This means that it needs to span in two principal directions, giving greater pertinence to the structural integretity of the joint between panels. All this amounts to the panels needing to be joined on site using incredibly robust joints. The sandwich panels overlap eachother with large lap joints, and the webs span over the seam to provide further strength. This is also made possible by the strenght of the novel T3 glue technology, which is stronger than the wood itself. The on site construction process consists of shoring the sandwich panels, applying glue at the seams, then pressing the seams together using a large array of wood screws.

on site construction


CLT Plates

The sandwich panel is comprised of two principal elements: the CLT (Cross Laminated Timber) plates on the outside, and the timber webs in the middle. Both elements need to respond precisely to the local forces within the structure to achieve the performance goals. Of principal concern is the optimal utilization of the anisotropic wood material. Wood is much stronger in the direction of the grain, and so grain orientation is paramount. Finite Element Analysis is used to generate a vector field of the bending and shear forces within the system. Then the elements are aligned to the force flow.

The first step is discretizing a floor slab into rectangular segments the size of the sandwich module. The rectangular segments should also span towards the columns. The CLT plates are then oriented based on the bending force vector field. This is determined by using both Sofistik and Karamba3D.

discretize floor slab


Web Alignment

Is is also crucial for the webs to be properly aligned to transfer the forces between the CLT plates. The web placement, orientation, and size is governed by two principal metrics: shear force magnitude and bending moment vector direction. A compromise between these metrics determines the final web design. First, web placement and density is governed by the concentration of shear forces, with higher concentration of shear forces necessitating higher web density. Then, this design is modulated by the bending moment vector field. The webs partially spread out to have more evenly distributed tributary areas, and their orientation is aligned to the bending moment vector field. After analyzing several design permutations in Sofistik, this modulation between shear and bending moment was the best performing design.



To showcase the novel Timber Building System, ITECH is constructing a pavilion on the University of Stuttgart campus. The pavilion is designed as a collaboration space/meeting room that can be utilized by the student community. It is enclosed by glass, with elegantly curved glass at the corners. The interior space is illuminated by electric lighting, and this showcases how the sandwich space can also be utilized for utilities.

This elegant and modest building is scheduled to be finished with construction in the summer of 2022. It serves as a test and a showcase of the novel design techiques developed at ITECH. If successful, the IntCDC excellence cluster plans to push this work forward towards the construction of a full scale building.