The current development in building energy efficiency towards nZEB buildings represents a number of new challenges to design and construction. One of these major challenges is the increased need for cooling 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 in midwinter.

Setting sustainable urban development goals and developing energy efficient solutions for buildings are crucial elements of climate action. Urban living is introducing new challenges both for architectural design and technical solutions. Ventilation systems have an important impact both on energy use as well as indoor climate and health in buildings.

Setting sustainable urban development goals and developing energy efficient solutions for buildings are crucial elements of climate action. Urban living is introducing new challenges both for architectural design and technical solutions. Ventilation systems have an important impact both on energy use as well as indoor climate and health in buildings.

Setting sustainable urban development goals and developing energy efficient solutions for buildings are crucial elements of climate action. Urban living is introducing new challenges both for architectural design and technical solutions. Ventilation systems have an important impact both on energy use as well as indoor climate and health in buildings.

Progressing the scientific basis of indoor environmental quality is essential to understand which aspects can be better optimised to substantially reduce energy use in buildings. In recent years, IEA Energy in Buildings and Communities (EBC) international research projects have been investigating for this purpose both indoor air quality and thermal comfort.

Progressing the scientific basis of indoor environmental quality is essential to understand which aspects can be better optimised to substantially reduce energy use in buildings. In recent years, IEA Energy in Buildings and Communities (EBC) international research projects have been investigating for this purpose both indoor air quality and thermal comfort.

Ventilation is recognized as a major element in strategies for minimizing the risk of COVID infection. REHVA and ASHRAE have developed guidelines taking existing evidence of long-range aerosol based transmission into account including the importance of ventilation.

Air infiltration in buildings has multiple consequences on energy use and indoor environmental quality which depend on the location and distribution of leakages. Among others, pollutant infiltration and air draft are highly affected by leakage distribution. In current practice, leakage detection is frequently performed together with an airtightness test.