There is very little research on the impact to building energy thermal comfort performance from non-thermally broken balconies. Balconies are a common feature of many high-rise buildings. They are exposed portions of the floor slabs, which, unlike the rest of the building envelope, are not thermally insulated. Building codes are somewhat ambiguous with how to treat balconies for thermal protection. Because of that, balcony slab connections act as large thermal bridges that cause excessive heat loss and gains from and to the interior space and poor indoor thermal comfort. This paper introduces the results of a research study that evaluated the effect of insulated thermal breaks in balconies on the envelope thermal performance and the overall building energy performance using an experiment and a parametric energy analysis.