The designs of future high-performance buildings involve optimal choices of design elements, from building materials to equipment types and sizings, as well as operations and controls configuration. Whole-building simulation and analysis, for example by EnergyPlus, has demonstrated a significant energy savings potential in a wide variety of design projects. The analysis results provide designers and engineers valuable information that influences the design of the building. However, currently, the analysis results must be reviewed by experienced architects, building engineers and modelers in order to figure out the possible design changes that might have the greatest economic and energy impacts on the building design. This is very time consuming since each new proposed change would require repeated simulations of the building performance. Automated building design optimization is missing from a large number of tools used for building performance simulation.