The Home Energy Saver is designed to help consumers identify the best ways to save energy in their homes, and find the resources to make the savings happen. The Home Energy Saver was the first Internet-based tool for calculating energy use in residential buildings.

The Home Energy Saver quickly computes a home's energy use on-line based on methods developed at Lawrence Berkeley National Laboratory. Users can estimate how much energy and money can be saved and how much emissions can be reduced by implementing energy-efficiency improvements. All end uses (heating, cooling, major appliances, lighting, and miscellaneous uses) are included.

The Home Energy Saver's Energy Advisor calculates energy use and savings opportunities, based on a detailed description of the home provided by the user. Users can begin the process by simply entering their zip code, and in turn receive instant initial estimates. By providing more information about the home the user will receive increasingly customized results along with energy-saving upgrade recommendations.

The Energy Advisor calculates heating and cooling consumption using the DOE-2 building simulation program (version 2.1E), developed by the U.S. Department of Energy. The program performs a full annual simulation for a typical weather year (involving 8760 hourly calculations) in about 10-20 seconds, after the user assembles the necessary information describing their home. Users can choose from 239 weather locations around the United States. DOE-2 performs a very sophisticated series of calculations, but the web-based user interface is relatively simple and results are distilled into a useful form. Default energy prices for each fuel and state are also available, or users can enter a specific price of their choosing.

The Energy Advisor calculates domestic water heating energy consumption using a detailed model developed by LBNL researchers. Users can see how household size, age of occupants, equipment efficiencies, and water inlet temperatures affect bottom-line energy costs.

By simply entering the number and approximate age of their major appliances, users can estimate their energy consumption, based on historic sales-weighted efficiency data. A very detailed module is also included to estimate energy consumption for lighting and dozens of miscellaneous gas and electric appliances, with default values based on data compiled over the years by LBNL researchers.

The results pages provide a list of recommendations--ranked by payback time--tailored to the particular home being evaluated. The user can vary the energy efficiency assumptions in many cases, as well as the retrofit costs and then recalculate the table. The results can be viewed on line, and via a detailed printable report which includes retrofit description and other details as well as links to additional information.

In addition to calculating energy use on-line, the Home Energy Saver's Making it Happen and Energy Librarian modules connect users to an expanding array of "how-to" information resources throughout the Internet. These modules help users successfully capitalize on the energy savings opportunities identified by the Energy Advisor module. Users benefit from a dynamic information base unparalleled by resources that could be published on static electronic media. These modules offer a host of links to practical information, ranging from lists of specific efficient products ... to tips about selecting a good contractor ... to information on what assistance your utility might have to offer. The site also features an extensive glossary and frequently-asked questions module.