Energy use in supermarkets varies according to the size and nature of products and depends on the external environmental conditions, opening hours, occupancy level and other internal heat gains. Since supermarkets’ energy performance depends on several factors, it becomes challenging to find buildings with similar characteristics that can be used as benchmark. This work attempts to collect data from a particular category of supermarkets – those with high percentage of frozen foods – in order to define a calibrated energy model baseline of the whole building. This paper reports on the data gathering of energy consumption and environmental conditions in two case-study buildings. The two stores have different HVAC systems (CAV, VRF). Preliminary results show that current energy use is similar for the two studied case-studies and within ranges reported in the literature for supermarkets of similar size. Monitored environmental data suggest that in the store with the VRF system environmental conditions are maintain within ranges set by the control system. Data also suggest that environmental conditions are dependent on external weather conditions as well as internal gains and HVAC system controls and so there is potential for further reductions in energy use by improving the design and thermal environment control of the stores to include low carbon strategies.