Thermal insulating plaster as a solution for refurbishing historic building envelopes: First experimental results

• Thermal insulating plaster is a possible option for historic building refurbishment.
• A new thermal insulating plaster vegetal based is investigated in the laboratory and infield on a real historic building.
• Vegetal aggregate materials lend higher mechanical properties to the plaster and allows higher layer thicknesses.
• The low thermal conductivity of the new material led to a significant reduction in the energy that crosses the wall.

In Italy, historic buildings constitute 20% of the built environment. Although historic buildings are usually excluded from the obligation of adopting specific energy standard, energy related aspects should be nevertheless faced and managed in order to exploit the building “usability” potential, to attain indoor environmental quality and energy efficiency conditions. The energy refurbishment of this kind of building is, however, a very complex matter that leads to a number of question concerning buildings conservation and valorisation aspects. A non-invasive technique, that is, the application of thermal plaster to the internal side of a building envelope, has been investigated in this paper. Thanks to its relatively easy installation and reversibility, thermal insulating plaster seems to represent a very interesting solution as it is able to offer a good compromise between energy and conservation aspects.The aim of this work is to present a thermal, vegetal based, insulating plaster, which has recently been developed within a research project, and to investigate its potential to reduce the heat flux exchanged through the vertical envelope of historic buildings, by means of measurements carried out in both the laboratory and in the field, for a real case application.