The durability of new surface layers of historical buildings is mostly estimated on the basis of experience because too few parameters are known for a reliable durability estimate. In this paper, main durability properties of innovative lime plasters with metakaolin admixture, namely water sorptivity, moisture diffusivity, water vapor diffusion coefficient, thermal conductivity and specific heat capacity are determined, together with the main mechanical parameters such as compressive and bending strengths. Comparative measurements with common lime plaster are done as well. On the basis of the experiments performed, it can be concluded that the analyzed lime-metakaolin plasters are suitable for an application in reconstruction of historical buildings.