Several models for automatic storytelling represent social norms by embedding into their structures social knowledge. In contrast, this model explicitly describes computational structures to represent knowledge related to social norms, mechanisms to identify when a social norm is broken within a narrative and a set of constraints and filters to employ such social knowledge during the narrative generation process. An implementation of the model employing MEXICA, an automatic storyteller based on the Engagement- Reflection creativity model, as source of story plots is presented. Lastly, the results of a survey are presented as a preliminary evaluation of the model.