Maintenance programming of civil and industrial buildings is a relevant problem, especially in a global situation where natural resources are increasingly limited. Accurately knowing the durability of building products and components, essential for a sustainable use of resources, becomes more and more important after the recent 18 January 2011 resolution of the European Parliament, which introduced the seventh requirement on construction products, specifically regarding the sustainability and therefore the durability of such. This study concerns the evaluation of the durability of some innovative coatings based on acrylic-siloxane resins containing several pigments, used for building external decorative finishing, applied in thin thickness and of different basic components. The parameters investigated are: the surface appearance and the maintenance of the original colour, significant for the aesthetic quality of the architecture. The paper presents the first results of the experimental study on coating materials, produced by Hydrate Ltd, performed according to ISO 15686, aimed at defining the Reference Service Life, by monitoring the behaviour over time of artificially aged samples in the climatic chamber and external exposed samples, as well as the monitoring of a case study.