The use of humidification and dehumidification systems increases the primary energy demand of a building significantly. Moisture buffering, moisture recovery and efficient use of ventilation are the only means to minimize the end energy demand and thereby also the CO2 emissions for humidification and dehumidification. In [1], various approaches by which the occupants themselves can regulate their indoor environment without the use of energy have been elaborated and their effect proven both computationally and by measurements. To model the moisture buffering transport processes of fibrous materials, in [2], a model was developed that can illustrate both the microscopic and the macroscopic hysteresis of the moisture storage and transport processes. In addition to the components performance (material characteristics) it is necessary to know the properties the whole room/building, taking into account various uses. For the validation of coupled room and building component simulations, an analytical solution of this unsteady problem is developed and presented in this paper. (C) 2011 Elsevier B.V. All rights reserved.