The demands for smart environments, which can help to facilitate as well as monitor independent living are increasing. With this comes a desire for decision support rules to process data recorded from such environments. However, testing and evaluating rules can be both time-consuming and indeed stressful for the inhabitants. Within this paper we propose a model, referred to as HomeRuleML, for representing decision support rules for smart environments. The motivating factor behind such a proposal is to provide a widely and freely accessible set of rules which can be openly used and exchanged within the research domain and beyond. This model has the potential to decrease the time required for deployment, and inevitability improve the inhabitants' quality of life. In the paper we explain in detail the structure of adopting this approach and also provide an indication of the typical types of software tools required for its use.