Concrete Repair in Heritage Preservation. A Review of Opposite Approaches at Antoniuskirche Basel and Liederhalle Stuttgart

Since the 1980s, two general approaches to concrete repair have emerged in the field of heritage preservation in German-speaking countries. They were first widely discussed during the work on Antoniuskirche in Basel (repair 1987–1991) and Liederhalle in Stuttgart (repair 1991–1993). The latter was recognized as a best practice example of localized repair and careful conservation, while the former was discussed as an exemplary case of renewal, imitating the original surface appearance. Although diametrically opposed in terms of conservation of material substance and appearance, both concepts are approved by official preservation authorities to this day. After some 30 years, we have revisited these two prominent cases of early concrete repair in heritage preservation to understand their genesis and to discuss their long-term consequences, also in the light of contemporary approaches. As our recent building survey and archival research show, their representation in the literature, and thus in public perception, has not yet taken into account the variety of repairs actually carried out. Despite their differences, the Antoniuskirche and Liederhalle projects suggest that a one-size-fits-all approach is rarely the best solution. Finally, our comparative analysis points to the potential of a history of architectural repair that is also relevant to building practice.