The goal of a Home Energy Management System (HEMS) is that of purposely shaping the cumulative energy consumption curves of domestic appliances by imposing suitable monitoring and control policies. The development of HEMS, like the development of general Cyber-Physical Systems (CPSs), is challenging, as it requires the exploitation of suitable methodological approaches which are able to deal jointly with the continuous and discrete behaviours of a CPS. In this paper, a methodological approach for HEMS is advocated which relies on the use of the Theatre actor system with hybrid actors. As a key feature, Theatre enables the same actor model to be used during the analysis, design, prototyping and implementation phases of the system. For property assessment, a Theatre model is reduced to Uppaal hybrid timed automata for analysis by statistical model checking. As a significant modelling example, a HEMS is proposed which implements an admission control strategy able to maintain the in-home energy consumption under a given threshold. Instead of reacting to an overload condition, the strategy is able to prevent an overload upfront by predicting the effect that the admission of a new load will have on the consumption curve of the whole system.