Overconsumption plays a big part in the current environmental crisis, making a shift towards sufficient consumption imperative. Since overconsumption is often a habit, triggering a stop and re-think process in the consumers' minds may be the way for reduction. Societal norms, proven effective for behaviour change, could disrupt consumption habits by combining a static (present norm) and dynamic (how the norm is changing) norm. This thesis explores the impact of combining sustainable and unsustainable framings of static and dynamic norms on consumer behaviour. A laboratory study exposed participants to four norm combinations before engaging in a shopping task. No significant differences emerged in the number of items selected or the time spent shopping across groups. However, a marginally significant interaction effect hinted at the potential influence of combined static and dynamic norms: participants selected the most items with two matching sustainable norms and the least with matching unsustainable norms. Notably, upon removing older participants from the data, this interaction effect disappeared and the effect of the dynamic norm became significant. Unsustainable norms triggered significantly higher negative emotions than sustainable ones, while sustainable norms elicited significantly higher positive emotions. Yet, neither significantly mediated the relationship between static and dynamic norms and item selection. These findings are relevant for marketeers and (communication) designers of companies seeking to engage in demarketing or government agencies promoting sufficient consumption. These results can lay the foundation for more extensive research into this combination of static and dynamic norms, which could be used to make stronger messages to promote both sufficient consumption and other sustainable behaviour.