An Encyclopedic Approach to the Conservation of 20^(th)-Century Architecture

The built heritage of the 20^(th) century concerns society in general: it is the background to everyday life and the stage of ‘past experience’. Therefore, recent past buildings should not be considered merely for their aesthetic features;they also have to do with physical well-being, social rituals and representations, as well as with associated concepts such as values and emotions. But conservation of 20^(th)-century heritage is not straightforward. It requires specific strategies as well as critical and operational tools, which are not part of the cultural background of the actors of the transformation of our cities (architects, engineers, heritage officials, etc.) and do not yet feature in current design teaching curricula in most universities. To fill these gaps, in 2008 four Swiss architectural schools (USI, EPFL, ETHZ, SUPSI) launched a research project titled ‘Critical Encyclopaedia for reuse and restoration of 20^(th)-century architecture’ (2009-2013). The article presents one of the outcomes of this research: the work developed by the section titled ‘Historical and Critical Tools for Conservation’, which will be published shortly. It provides readers with the cultural, theoretical and critical frame of reference required to understand recent architectural heritage in its widest sense: as a historical, symbolic and aesthetic resource, but also as being endowed with social, economic and ecological value. By examining theories and doctrines which have developed over time and thanks to the ex­emplary nature and variety of the selected cases, it provides a historical appraisal of how intervention in the field of recent heritage has evolved over the past 60 years. Furthermore the oeuvre presents intervention tools in action: by analysing a vast array of case studies which address the main areas of conservation practice (historical and critical research, analysis of materials and technical features, identification of compatible new uses, regulatory compliance), it provides a methodology to develop concrete and appropriate criteria for any specific case.