single-family home

Although the physics concerning air pressures in buildings don’t differ between countries, often different reference values of the pressure difference over the envelope are used to determine air tightness and ventilation characteristics. The air transfer devices for natural ventilation, integrated in the façades or the internal building structure, are characterized at a pressure difference between 1 and 20 Pa depending on the country. For example, Belgium uses 2 or 10 Pa as a reference, the Netherlands adopts 1 Pa, whereas France applies 10 or 20 Pa.