After 2000After , 2010, energy and heat savings became a key concern of the European Parliament and the Council of the European Union. The result of these efforts and activities was, in particular, the introduction of the Energy Performance of Buildings Directive (EPBD I., EPBD II., include EPBD II. recast), into the legal ambience of the EU Member States. The resulting requirements are mainly reflected in the areas of energy decrees and normative regulations and place high demands on the gradual reduction of energy consumption and overall sustainability. The new thermal-technical and energy legislation and ever-stricter criteria of the European Union require among other things that measures taken towards overall improvement of building performance should include better quality thermal insulation of building envelopes of both, new and refurbished buildings. However, one has to evaluate real impact of improved thermal insulation and energy saving parameters within the context of the overall structural and environmental design of buildings by also taking into account the ramifications of such improvements to building structures. On the one hand, there is a qualitative energy improvement; on the other hand, we encounter new manifestations of defects and failures in the form of biodegradation of facades. The aim of the paper is to present a case study based on monitoring of prefabricated apartment buildings, laboratory analysis of biodegradation microorganisms and model calculations, and to explore how increasing the thickness of thermal insulation can negatively affect the condition of the building facade and how they can start biodegradation processes in the form of mosses, lichens and algae. The paper shows the need for the interaction of all interdisciplinary contexts that lead to quality reconstruction and renovation interventions, the aim of which is to extend the life of a panel residential housing by at least another twenty years.