Challenges in the sustainability assessment of historic buildings

In recent years, several methods and certification systems have been established to assess the sustainability of buildings. However, these methods often neglect historic buildings due to their non-standard characteristics. Such characteristics, often rooted in long cultural traditions, can be found in a wide variety of traditional structures, from rural homes, to houses and buildings in small towns to churches, cathedrals, and even castles. The lack of a standard method by which to assess the sustainability of historic buildings is a major gap in the field of green building and has led to an increasing number of researchers and practitioners asking how to best sustainably preserve these historic buildings, in the absence of any standard approach. The Fraunhofer Institute for Building Physics is conducting a project entitled "Energetic analysis and optimization of internal wall insulation (abbreviated "Internal Wall lnsulation") in which diverse thermal insulation materials will be tested and evaluated for historical buildings. The objective of this project is to find thermal insulation materials and constructions that are suitable for historic buildings. The materials should ideally be reversible and should have both an excellent physical and environmental performance. The project is located at the Fraunhofer Centre Benediktbeuern and experimental work will happen in both the historic building of the Old Cooperage and at the Outdoor Test Facility of Fraunhofer IBP at Holzkirchen. The IBP Department of Life Cycle Engineering (GaBi), together with experts for building conservation from Fraunhofer IBP group of Preventive Conservation and Preservation of Cultural Heritage in Holzkirchen, will conduct a life cycle assessment (LCA) of the various thermal insulation materials tested over the course of the project in order to assess the materials' sustainability as a new, additional part of the historic building. This paper gives an overview of the challenges associated with assessing the sustainability of historic buildings and examines a case study via the project "Internal Wall Insulation". Sustainability of heritage preservation, life cycle assessment and its applicability in the building sector, and possible solutions for the challenges in the sustainability assessment of historic buildings are all discussed