Summarises the concept of indoor climate classes (ICC) for the assessment of interstitial condensation risk and describes how the pivot values that define the borders between classes can be calculated in worst-case constructions with hourly test reference years of climatological data, taking radiation into account. Discusses the construction and occupancy parameters that affect the ICC and develops methods of correcting the pivot values to a set of standard parameters. Analyses data from 33 meteorological stations, ranging from southern Italy to northern Finland and central Canada, to provide the ICC values and limits on moisture production within a house. States that in many climates surface condensation or mould growth is likely to occur before the onset of interstitial condensation.

KEYWORDS: year 1995, Buildings, condensation, indoor, microclimate, designing, climate.