Describes how the introduction of mechanical HVAC equipment has led to a divorce between building design and climate. Explains how building energy use and HVAC equipment size can be reduced by effective integration of the architectural and mechanical designs. Provides a brief description of each step in this process. Confirms the potential reduction in energy use by hourly energy use simulations of a hypothetical building which showed the direct relations between building shape and orientation to energy use. Shows overall potential energy savings of 31%.