Life-Cycle-Assessment (LCA) becomes more and more an important tool for industry to choose the adequate material or technique leading to an expected product quality from environmental point of view. As the environmental aspects are just one part of the decision making process, economical aspects have to be implemented as well. Sustainable construction is a major driving force of building and construction technology. The building sector uses extensive quantities of natural resources, raw materials and energy.

Since the mid 70's, the construction industry has made significant advances in energy conservation and improved indoor conditions. These improvements, however, are shadowed  by an increase in building envelope problems to include water penetration, condensation on and in roofs and exterior walls and cladding damages in many of our newer buildings; These problems have been attributed to uncontrolled air leakage.