Freeze-Thaw Risk in Solid Masonry: Are ‘Hygrothermal Response Based‘ Analyses Mandatory when Studying the Sensitivity of Building Envelopes to Climate Change?

. The 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) reports important evolutions in the climate system. These changes are likely to affect the durability of the built environment. Although many contemporary studies investigate the future energy efficiency of buildings, research on the impact of climate change on the hygrothermal behaviour and degradation of building envelopes is rather scarce. Using climate projections, we studied the advantage of ‘hygrothermal response based’ analyses over ‘climate based’ analyses when assessing the impact climate change on façades. This paper presents a sensitivity study on solid masonry wall assemblies, before and after internal retrofitting, using three RCP (Representative Concentration Pathways) projections of the ALARO-0 Regional Climate Model at the grid point of Brussels (BE). The findings suggest the necessity of a ‘hygrothermal response based’ analysis to study the sensitivity of the building envelope to climate change. Moreover, the largest sensitivity is observed for RCP 8.5, the scenario having the highest projected greenhouse gas concentrations by the end of the century.