User behaviour plays a key role in the energy demand of residential buildings, and its importance will only increase when moving towards nearly Zero-Energy homes. However, little detailed information is available on how users interact with their homes. Due to the lack of information, user behaviour is often included in building performance simulations through one standard user pattern. To obtain more accurate energy demand simulations, we need user patterns that capture the wide variations in behaviour without making simulations overly complicated. To this end, we developed a probabilistic model which generate realistic occupancy and activity sequences respectively. This paper reports on the methodology used to construct the model based on Belgian time-use data. The modelling of individual sequences based on this method enables to include highly differentiated yet realistic behaviour in building simulations. By linking the model to the use of appliances, individual household load profiles may be obtained.