Effect of building and installation design on PM2.5

People spend more than 80% of their time indoors. In contrast to ambient air, no (legal) limits for indoor particulate matter exist, although there are WHO guidelines. In the Netherlands a measurement protocol to determine the PM2.5 in office buildings has been developed including 5 quality classes. However at the moment no simple guidelines or models are available which can support the design and in-use phases to predict the PM2.5 concentration in office buildings and schools.