Life Cycle Assessment (LCA) analysis of renders and paints for the restoration of historical buildings

A significant percentage of the building stock in Europe was built before 1950, hence the restoration, retrofitting and renovation of historical buildings is of paramount importance not only for society, but also for the overall sustainability of the construction sector, which is known to have a huge environmental impact. In particular, the applicationof new paints and renders is extremely common in the restoration interventions carried out in historical buildings. In the selection of these materials, it is important to consider that they must comply with compatibility requirements, in terms of low stiffness and high water vapour permeability, not to give rise to premature defects and detachment. However, their environmental impact is basically never evaluated. In this study, a preliminary evaluation of the environmental impact of some selected rendersand paints for the restoration of historical buildings by Life Cycle Assessment (LCA) analysis was carried out. This analysis was performed using the information that are supplied by the manufacturers of the materials (as reported in the technical data sheets), so from the point of view of the designers, who must select among a range of commercial alternatives. Both ready-mix dry renders and mortars purposely prepared in the building site, with or without paint, mechanically or manually applied, were analysed. The paint, notwithstanding its low amount with respect to the render, seems to have a very high impact. The results also suggest that an evaluation of these materials by LCA is definitely not easy, mostly because some key characteristics of materials which are needed for this analysis are currently not reported at all in the technical datasheet, thus jeopardizing a proper evaluation of their environmental impact.