Conceptual procedure to achieve good air tightness in large buildings, using the example of the EU press centre of the council of ministers

Experiences of the past years showed that it is possible to achieve a considerably better air flow rate in large buildings than it is targeted by the regulation of energy saving. The cause is not that the quality of air tight levels is considerably better in large buildings than in single-family houses. These buildings rather have a bigger internal volume (reference volume) compared with a relatively small surface (envelope surface) through which air change takes place. In order to achieve the quality of the air tightness level, which is similar to the one of a single-family house, it is useful to assess the envelope surface covered leakage flow q50 instead of the air change rate n50. Q50 indicates how high the air exchange is at 50 Pascal for a square meter of building envelope surface per hour.