The unbalanced introduction of energy conservation measures has generated an increasing number of condensation problems both in new and existing buildings. These problems not only constitute a barrier to the successful introduction of energy conservation, they also result in severe social problems and can be seen as affecting building quality.
The phenomena observed are related to building construction practices and also to changes in human behaviour with regard to energy use (lower inside temperatures, less ventilation). Statistical studies in different countries have shown that the problems due to condensation are widespread and that a well co-ordinated international effort was necessary, not only to study their origin and implications, but also to find solutions to them.
This task has provided architects, building owners, practitioners as well as researchers, with a better knowledge and understanding of the physical background of these phenomena (critical) conditions for mould growth, material characteristics related to the problems, it has also provided them with better computation models taking air, heat and moisture transfer into account in order to predict properly the phenomena of surface condensation and possible solutions to avoid it. Finally it has developed energy conserving and cost effective strategies and complementary design methods, techniques and data for avoiding condensation and mould growth in new buildings and preventing re-occurrences or further degradation in problem buildings.