Timber is widely recognised as a sustainable building material. Yet engineers face a gap in knowledge when analysing walls with window openings. At present, these walls are treated as “voids” in structural models. This approach makes buildings less efficient and increases the need for steel anchors or concrete cores.

A research team from Empa, Bern University of Applied Sciences, and ETH Zurich is working to change this. With support from the Swiss Federal Office for the Environment (FOEN) and industry partners, they are testing how such walls behave under pressure. The goal is to include them in structural calculations and improve the use of material.

Large-Scale Testing

In Empa’s construction hall, researchers built two-storey timber walls with different window openings. They then applied strong lateral forces until the walls failed. Cameras and sensors recorded the results in detail.

The tests proved that walls with windows can withstand large horizontal loads. These findings now feed into a new computer model. With this tool, engineers will be able to design timber structures that rely less on concrete cores or heavy steel anchors. The result: more efficient buildings that use fewer carbon-intensive materials.

Designing with Confidence

The results offer clear benefits for architects and designers. Timber buildings can now be planned with greater accuracy, saving both time and resources. At the same time, the method supports sustainable design strategies by maximising the structural potential of renewable materials.

The next step is to refine the computer model for everyday use. Researchers are simplifying it so that engineers can apply the method quickly and effectively in practice. Close cooperation with industry ensures that the tool will be ready for real projects soon.

Source & photos: Empa