Review of the “Lime & Clay” Expert Discussion at the Mauerbach Charterhouse, April 29, 2026
On April 29, 2026, as part of the EU project TIME4CLAY&LIME, approximately 50 experts from the fields of painting, historic preservation, architecture, research, education, and construction gathered at the Kartause Mauerbach for a technical discussion on “Lime and Clay.”
The event focused on traditional mineral and natural building materials, their artisanal processing, and their significance for historic preservation, sustainable construction, and contemporary building culture. It became clear that lime and clay not only have a history of use stretching back centuries, but also offer valuable solutions to current challenges in resource-efficient and environmentally friendly construction.
Expert insights were provided by Mag. Astrid Huber-Reichl of the Federal Monuments Office, director of the Information and Continuing Education Center for Historic Preservation; restorer and lime expert Hannes Weißenbach; master painter Alexandra Vierlinger, geologist and building materials scientist Dr. Karl Stingl, master painter and author Gerold Ulrich, and architect and clay researcher Univ.-Doz. Dr. techn. Hubert Feiglstorfer.
Mag. Astrid Huber-Reichl placed the unique qualities of lime as a building material in a broader context and spoke of the “economy of simplicity—and thus the ecology of simplicity.” This approach points to a method of construction that relies on tried-and-true materials, straightforward processes, and a mindful use of resources.
Hannes Weißenbach highlighted just how essential hands-on experience and a direct understanding of a material are in this context: “Hearing, feeling, smelling, seeing—that’s something no measuring instrument can do.” This also brought to light a central message of the expert discussion: Expertise does not arise solely from measurement values and technical data, but equally from experience, observation, and hands-on work with the building material.
Clay, one of humanity’s oldest building materials, was also a focus of attention. Especially in light of today’s demands for sustainable and healthy construction, the material is regaining importance. Assistant Professor Dr. techn. Hubert Feiglstorfer highlighted in particular the building physics properties of clay: “The true qualities of clay lie in its ability to release moisture.”
In addition to scientific and theoretical perspectives, hands-on instruction played a central role. The academic program culminated in a vivid outdoor demonstration of lime slaking. The experiment was deliberately conducted on a small scale in a wooden trough so that the participants could directly observe and understand the process.
Afterward, the professional exchange continued in a relaxed atmosphere over wine and bread in the Baroque garden of the Mauerbach Charterhouse. The discussions provided an opportunity to bring together experiences from various fields, strengthen professional ties, and explore new perspectives on working with lime and clay.
The expert discussion thus impressively demonstrated how important the exchange between the skilled trades, historic preservation, research, architecture, and education is for passing on traditional knowledge and linking it to current requirements for sustainable building practices. This is precisely where the EU project TIME4CLAY&LIME comes in: to highlight existing knowledge, pass on expertise, and strengthen the use of lime and clay for future generations.
