The energetic retrofit of historic masonry buildings : focus on Central and Northern Europe

40% of the total energy consumed in Europe is consumed by building operation and usage (Itard, et al., 2008). In the temperate climate of central and northern Europe, a significant proportion of this consumption is attributed to building heating during the winter months. Although recent trends in European legislation favor an increase in thermal efficiency of building enclosures for new constructions, the majority of the building stock consists of buildings built to a lower standard of energy efficiency.

Over 56 % of the building stock in the central and northern European countries was built before 1970, when the first building energy efficiency regulations were adopted across Europe (Itard, et al., 2008). Even if current regulations require significant energy efficiency measures (EnEV 2009 in Germany requires a maximum heating energy consumption of 50 kWh/m2a) and the trend is to increase the standards even more, a vast portion of the building stock will have been built to much lower standards. Retrofitting existing buildings represents thus a priority, if a significant reduction in energy usage for buildings is to be achieved. There is a great opportunity in tackling this problem, especially when keeping in mind the fact that most of these inefficient building require significant renovation measures, as the lifespan of their systems comes to an end

The case of historic masonry buildings across Europe is especially relevant, as they pose special challenges related to the historic preservation of facades and even interiors. It is thus the aim of the present research to compile a set of principles and technologies that can be used for the thermal retrofit of historic buildings.