This paper presented the findings related to moisture transfer between indoor air and hygroscopic wood-based material in heated closed buildings. Humidity conditions inside the heated buildings have a significant impact on the people's living comfort, the perceived air quality and human health. Therefore, people's life quality may be improved with the implementation of appropriate hygroscopic wood-based materials which are suitable for indoor usage. In this study, moisture transfer of wood-based materials and relative humidity in the heated saloon of an apartment located at Karadeniz Technical University Housing (Trabzon / Turkey) were investigated numerically. In the theoretical calculations were used ideal gas and sorption equations. SPSS-22 statistical software were used for statistical analysis. The results showed that under the indoor climate conditions, the moisture transfer between the air and the hygroscopic wood-based materials usually provided balancing effect on the relative humidity.