Combined Heat and Power (CHP) systems are known for a long time and are well established especially in the industrial sector where they allow interesting energy savings. However, the application of this technology in the residential and small tertiary sectors remains difficult due to the irregularity and the low heat demand during certain months of the year. The “Smart Micro Cogen” project focused on evaluating the potential of micro CHP systems (≤ 50kWe) in the Belgian building stock (residential and small tertiary sector) by means of dynamic simulation using TRNSYS 17 software. This work provides the hypotheses allowing representing the Belgian residential building stock and the different elements taken into account in the modelling and simulation of a complex HVAC system including a micro CHP system. Some results of the various simulations performed will be presented to show the robustness of the proposed modeling. ; Smart Micro Cogen