How Buildings Can Live Longer Thanks to Digital Fabrication

Matthias Brenner, doctoral student at the Chair of Construction Heritage and Preservation at ETH Zurich, uses digital fabrication to produce customised spare parts for a complex façade made from bespoke metal elements. He aims to extend their useful life. Innovative technologies such as digital fabrication, robotics and 3D printing are primarily used in the construction industry to realise new forms. Their application for existing buildings, the maintenance and repair of existing buildings, has hardly been researched to date. However, this could make a major contribution to extending the life cycle of buildings.

Matthias Brenner analyses the potential of digital fabrication for the repair of high-tech architecture from the 1980s. However, it is precisely these buildings, which were spectacularly constructed in the 1980s using innovative building materials such as plastic or aluminum, that present us with new challenges in terms of ageing. A large proportion of the buildings and façades constructed during this period are now in need of repair. Dealing with these new materials and constructions differs from the ageing processes of conventional constructions. The "CLA" university building at ETH Zurich is an ideal first case study due to its complex and expressive façade construction.

The CLA building on Clausiusstrasse in Zurich serves as the first case study. Photo: Matthias Brenner

Specific Reproduction of Spare Parts

The CLA building on Clausiusstrasse in Zurich was completed in 1998 after two construction phases. The multi-layered and open technical façade is a special eye-catcher and also serves as a sun protection element. The construction consists of customised special components that were manufactured exclusively for this façade. Should one of the bespoke components be damaged, it would be difficult to repair or replace - conventional spare parts are not suitable and individual components are no longer available. In addition, detailed construction plans are no longer available, which makes the production of replacement parts very difficult. The replacement of the entire façade system can be avoided by the targeted reproduction of individual defective elements.

In the Spirit of High-Tech Architecture: Digital Fabrication

To remain true to the spirit of high-tech architecture in façade maintenance, repairs are being trialled using state-of-the-art production technology: individual parts of a façade can be reproduced in a targeted manner using digital fabrication and replace the defective parts in the façade system. In the case of the CLA building, "reverse engineering" was used due to a lack of documentation and plans. A digital 3D model was calculated using photogrammetry and reconstructed using a point cloud. In collaboration with Prof. Dr Markus Bambach (ETH Zurich), the new production technology Wire-and-Arc Additive Manufacturing (WAAM) was used for the 3D printing of the special part. With this technology, the material is only applied where it is actually needed. The resource-efficient and sustainable process is therefore very promising for extending the service life of buildings and their façades with the help of digital fabrication.

The Chair of Construction Heritage and Preservation (Prof. Dr. Silke Langenberg) at ETH Zurich is dedicated to the responsible treatment of historic buildings. This plays a central role in repair and maintenance in particular. The new CAS ETH ReMain (Repair and Maintenance) programme deals with such approaches.