Although much of the commercial sector infrastructure for the next century is currently under construction or is in the planning stages, little has been done in communicating how potential global warming might change the energy consumption characteristics of the building stock. The research discussed in this article advances the literature on how climate change affects commercial sector energy demand systems. It projects the effects of climate change on commercial energy demand in the United States at the national level. The article relies heavily on time-series regressions of monthly energy consumption by building on monthly heating and cooling degree days. It provides empirical results for the effects of climate on a projected building stock in the year 2030 and examines the prospects for saving energy with advanced building designs in the context of potential global warming.