The problematics with building-related moisture, microbial growth and health has been studied in Finland during the last 15 years. The approach has been a multidisciplinary effort to understand the different aspects of moisture damages, microbial growth in materials, exposure to humans, health effects and their mechanisms. Prevalence studies have shown that half of the housing stock has signs of previous or present moisture faults, and the problems are also common in schools and offices. The association between moisture observations and respiratory health outcomes has been shown. Only a minor part of the health effects are IgE-mediated allergies. The current research focuses on efforts to understand the exposure and inflammatory mechanisms of the health effects. Measured as airborne concentrations of viable fungi and bacteria, the exposure cannot necessarily be shown in a satisfactory manner. Research on microbiological behavior of materials will provide new understanding on the microbial ecology of building and the whole problematics.