This paper presents proposals on how to apply software product lines in the context of smart buildings control systems. Our study is held in the context of the RIDER (Research for IT as a Driver of EneRgy efficiency) project, which is led by a consortium of several companies and research laboratories. The paper highlights various issues, including issues related to traceability, variability and automatic transformations in our specific application context. It then proposes solutions to apply existing concepts like feature diagrams, model-driven transformations and component-based architectures, or appropriate extensions of these concepts, in this context. Furthermore, we globally propose an approach to federate the various components involved in smart buildings, and to capitalize on the developed IT components by reusing them at the lower cost in the construction of future buildings.