This paper presents and demonstrates a method for evaluating how the effectiveness of weatherization treatments varies geographically due to difference in climate and housing stock. American Housing Survey data was used to describe the low-income urban housing stock in six different cities representing a range of geographical and climatic areas. These data were then used to drive the Home Energy Saver model to simulate current energy consumption and expected energy savings from a combination of three weatherization treatments: replacing a standard thermostat with a programmable thermostat, installing attic insulation, and envelope air sealing. Modeled energy savings were compared to observed energy savings. Results show that greater energy saving potential generally exists in cities with colder climates, but the effectiveness of different weatherization treatments also varies with differences in regional housing stock and space conditioning equipment. This study's results and methodology could be used in future research to compare the cost-effectiveness and carbon reductions of potential weatherization programs. (C) 2013 Elsevier B.V. All rights reserved.