ENERGY STAR® has just launched their new Home Improvement Toolbox. The centerpiece is a calculator developed by the End-Use Forecasting Group and the Home Energy Saver Team at LBNL. The tool is powered by HES and uses the same underlaying data, with a simplified user interface. It features customized upgrade recommendations, a new interactive module on cost-effectiveness, and content pertaining to non-energy benefits of efficiency improvements This project provides an example of how a web-based energy calculators can utilize the basic HES engine. The site was sponsored by the U.S. Environmental Protection Agency (EPA) and the Partnership for Advancing Technology in Housing (PATH).