Public recognition of climate change and its repercussions has sparked concern about sustainable practices that only continue to grow. This concern has resulted in more stringent energy consumption standards, such as the Toronto Green Standards, which add additional measures that practitioners must consider during their design. Thermal bridging, defined as localized heat flow typically due to discontinuities in building envelope insulation, causes substantial thermal energy loss in structures. This loss is especially prevalent in areas requiring significant energy for heating and cooling. This paper examines the use of different modelling software, THERM, Ansys, and StarCCM + , to predict the temperature change in concrete floor slabs resulting from the balcony, which is exposed to the exterior temperatures. The software was tested in 2 stages and judged based on simplicity, analysis time, and accuracy. The first stage compared their results to experimental data by others. The second stage consisted of a case study where the linear thermal transmittance was estimated for two slabs, representing cases with and without a thermal break. This paper aids practitioners in numerically estimating reinforced concrete slab temperatures when they are connected to balconies exposed to the external temperature.