Reducing the energy consumption in existing buildings became one of the critical challenges at the beginning of the 21st century. Several types and levels of retrofits are now being implemented in the building stock. To obtain a better understanding of the actual impact of these actions, evidence-based research has been playing an increasingly important role. This paper describes the collection of data on measured pre- and post-retrofit energy consumption of a group of buildings in the U.S., in order to distinguish the impacts of different levels of retrofits. In particular, the goal has been to distinguish how retrofits including facade improvements compare to those centered exclusively on internal systems. Additionally, energy data was collected for a subset of non-retrofitted buildings and used as the control group. The regression model revealed greater energy savings from retrofits including the facade as compared to those that excluded it. However, those savings are modest considering the energy reductions that are anticipated from deep-energy retrofits. Other relevant factors, such as occupants and their behavior, are vital for determining the value of retrofits and need to be incorporated in the next phases of this study.