The current development in building energy efficiency towards nearly-zero energy buildings represents a number of new challenges to building design and construction. One of the major challenges is the increased need for cooling present in these highly insulated and airtight buildings, which is not only present in the summer period but also in the shoulder seasons and in offices even during occupied hours in winter. In most post-occupancy studies of high performance buildings in European countries elevated temperature levels is the most reported problem, especially in residences. Designers underestimate the cooling need and often use too simplified design methodologies to assess the risk of overheating. Ventilation can be an attractive and energy efficient solution, as it is already present in most buildings and because it can both remove excess heat gains as well as increase air velocities and thereby widen the thermal comfort range. As cooling becomes a need almost all year around the possibilities of utilizing the free cooling potential of low temperature outdoor air increases considerably. 

This projected was completed in 2013 and taken up by EBC's Annex 62 "Ventilative Cooling".