Guidelines for internal Insulation of historic Buildings

Internal insulation is often the only possible solution when improving the thermal performance of solid walls of historic buildings, as many of these have architectural or cultural values. However, as internal insulation is regarded risky from a moisture perspective, guidelines are needed. The paper presents a new set of guidelines that combine written guidelines, a web-based preliminary assessment tool and a website that can be used independently of each other. The website provides simple ways of assessing the building to determine whether internal insulation is feasible in the specific case and what needs to be done before it can be applied. It also describes different failure mechanisms. The website includes links to information (written guidelines), described for different types of users, depending on their level of expertise. The web tool is based on an extensive number of simulations of hygrothermal conditions within a solid wall depending on location, orientation, wall type and thickness, and insulation type and thickness. The web tool determines the risk for mould and algae growth in a probabilistic way and determines heat loss and CO2 emission before and after renovation through 1 m of the wall. The guidelines, the website and the web tool are developed in RIBuild, a research project funded by the European Commission, running from 2015 to 2020.