Mitigating climate change and its impact requires intensive efforts to reduce greenhouse gas emissions, transition to renewable energy sources, and implement sustainable practices. Intermittent heating is considered a sustainable and effective way to achieve energy savings compared with continuous heating mode. However, recent studies have found that energy savings from intermittent heating depend on several factors, namely the building envelope solution. Therefore, this work intends to fill the research gap by comparing the energy efficiency and thermal performance of different construction systems, using two real-scale test cells, one built with a Light Steel Framing (LSF) solution and the other with concrete and Hollow Brick Masonry (HBM) solution. An experimental monitoring campaign was performed during the heating season, aimed at analysing the energy consumption, the responsiveness of the test cells to the heating system, and the influence of the outdoor climate on energy consumption, considering different heating strategies (intermittent patterns and continuous). In general, the LSF test cell registered lower energy consumption when compared to the HBM test cell. However, the LSF test cell presented significant fluctuations of the indoor temperature, confirming that it is more susceptible to the outdoor climate conditions. This research concluded that a system with lower thermal inertia has superior energy saving potential.