According to the European commission, “Buildings are responsible for approximately 40% of energy consumption and 36% of carbon dioxide emissions in the EU. Currently, about 35% of the EU’s buildings are over 50 years old and almost 75% of building stock is energy inefficient, while only 0.4-1.2% (depending on the country) of building stock is renovated each year. Therefore, more renovation of existing buildings has the potential to lead to significant energy savings, which could reduce the EU’s total energy consumption by 5-6% and lower CO2 emissions by about 5%.”
These energy savings contribute to a better Indoor Environmental Quality -IEQ- however to be sure a good comfort is provided to the building occupants, international standards are used as a guidance for measurement of key parameters like air speed, temperature, relative humidity, lighting and sound level.