One of the most important purposes of a building is to protect the occupants from the climate – humidity, water, cold or heat. As a famous architect once said, architecture is “our third skin”; i.e., the third layer after skin and clothing. This layer has been improved and optimized throughout the history of constructional engineering.
Although they did provide direct protection from cold and damp, heat and rain, houses had considerable shortcomings as regards healthy living, well into the last century. In particular, the combination of poor ventilation and cold internal walls due to the high heat transfer coefficient of the building materials caused many illnesses. Medical experts noted serious health problems in the occupants of apartment blocks, due to poor thermal insulation.
In addition to health problems, however, the numerous problems associated with condensation also led to considerable structural damage.