The goal of this paper is to propose a real time solution to validate energy smart-home strategies that support Demand Side Management done by direct control. The validation concerns the appliances under control. An Energy Management System globally controls the appliances of a house, satisfying the subscription power limits. A hardware-in-the-loop test bench, based on a real-time simulator called RT_LAB, is proposed to exemplify the validation mean: it is used to assess the performances of an energy management strategy for a thermal zone based on the control of a heater. Physical devices are introduced into the simulated system to check whether they can support the control strategies.