The analysis of more than 5600 microbial material samples, taken from over 700 Finnish public buildings, shows that there is no statistically significant difference in the presence of mold growth between the indoor air problem and reference buildings. Hence, presence of microbial growth in structures does not explain reported symptoms of building users. According to the official Finnish guidelines, material samples were cultured on three or four culture media and the classification of the results were based on both the number of microbes and the identification of the moisture indicator fungi. However, the addition of the Hagem media as the fourth culture media in 2016 has had effect only on the results of less than 2 % of the samples. Therefore, it is justified to omit the Hagem media to reduce the amount of work and costs of the building condition surveys.