This report presents the results of a state-by-state analysis of the potential energy and cost savings from improving compliance with building energy codes to 100 percent from current levels. The report also examines 45 statewide compliance evaluation studies, providing a summary of evaluation methods and key findings. Evidence in most states indicates that staggering rates of non-compliance, as high as 100 percent in some jurisdictions, have eroded the gains from energy code development and adoption.

It is clear that city must be part of the solution if an urbanizing world is to grapple successfully with ecological challenges such as energy depletion and climate change. A system dynamics model was developed in this study using STELLA platform to model the energy consumption and CO2 emission trends for the City of Beijing over 2005–2030. Results show that the total energy demand in Beijing is predicted to reach 114.30 million tonnes coal equivalent (Mtce) by 2030, while that value in 2005 is 55.99 Mtce, which is 1.04 times higher than the level in 2005.