Building designs at the moment of commissioning include the initial (building and technological) moisture. Thermal insulation systems influence on the yield of the initial moisture from the structures. However, there are no specific design requirements about determining initial moisture content in insulation systems.

In this article the features of the initial period of operation on an example of aerated concrete are defined: the results of field surveys and calculations are shown and compared. On the basis of this comparison basic advice on the accounting features of the initial period of operation of autoclaved aerated concrete structures with external insulation are given.