- Story
Digitalisation simplifies the renovation of historic windows
31.03.2025 BFH has optimised and in part digitalised the renovation process of historic windows. This saves time and money, making the energy-efficient renovation of old windows more attractive.
Key points at a glance
- At present, the renovation of historic windows is usually done by hand. As a result, it is time-consuming.
- BFH has optimised and in part digitalised the renovation process.
- The digital process saves time, making the renovation of old windows more attractive.
Why did the researchers want to digitalise the process of renovating historic windows?
The energy-efficient renovation of historic windows is complex and time-consuming. Cutting the glass out of the window frame and replacing it with better insulated glass is usually done by hand. This labour-intensive work requires a great deal of strength. It can also be hazardous to health due to the substances contained in the putties and paints.
Quadra Ligna AG, a company that specialises in the renovation of old windows, asked BFH to develop a solution to speed up the process with machine processing and optimised data acquisition.
The digital applications reduce the time required to renovate windows by more than 50 percent.
How did the researchers proceed?
The project team developed an app that allows a person to record the dimensions of the window panes and transmit them electronically to a robot. The robot can then cut out the old panes with millimetre precision.
The researchers also used the app for the design of the digital interface for data transfer to the robot and for the mechanical process used for cutting out the old window panes.
How does the digitalised process for replacing window panes work?
Thanks to digital tools, the window measurement can be done by one person instead of two. After the fully automatic removal of the panes, the wider modern triple glazing is fitted and secured in the old window sash by means of a custom-made wooden frame. This part of the job is still done manually.
The digital applications replace on the one hand less attractive manual work processes, while on the other hand reducing the time required to renovate windows by over 50 percent. As a result, it is now more interesting for owners of properties with historic windows to replace them with state-of-the-art insulation glass.
What was the main challenge you had to overcome?
The main challenge for the project team was to create the digital chain – from capturing the window data to cutting out the glass. They had to develop the interfaces themselves, in addition to the application and the editing process, because there were no standard applications.
More about the project and the BFH expert behind it
BFH worked with Quadra Ligna AG, a company that specialises in the renovation of historic windows, to digitalise the renovation of historic windows.
The project was led by Eduard Bachmann, a wood engineer who works in the Digital Fabrication group at the School of Architecture, Wood and Civil Engineering.
In addition to his teaching activities, he conducts research in process automation, digitalisation, digital production systems in the wood industry and in the Workshop of the Future.
How does the project benefit society?
Historical windows are a cultural asset and, as such, are worthy of protection. The simplified, energy-efficient renovation of these windows is a welcome contribution to the sustainable development of our society. The digital application automated unattractive tasks, helping to address the industry’s growing skills shortage.
