1. A computer based method for evaluating different building designs, the method comprising: generating a first set of different building massing configurations using a shape grammar; storing the generated first set of different building massing configurations in a building massing library; reducing the first set of different building massing configurations according to a parameter search to form a second set of different building massing configurations, the second set being a subset of the first set; using the second set of different building massing configurations to evaluate an aspect of a building system; and further comprising: calculating a normalized energy use index for the second set of multiple different building massing configurations, wherein the normalized energy use index for each of the multiple different building massing configurations is normalized against a reference energy use index of a reference building; ranking the multiple different building massing configurations by the respective normalized energy use indexes; and selecting at least one of the different massing configurations for display on a graphical user interface according to the ranking.