Photovoltaic /PV system at the home of Liz & Joe Rowland in Owego NY, participants in the Ithaca Green Building Open House.

Solar power can provide both thermal and electric energy for both residential and commercial buildings.

Green Rating Systems

When considering how to quantiify the "sustainability" or the "greenness" of your home, you may want to take a look at what other established rating systems consider important. Whether you are looking to have your project certified and achieve specific levels, or are merely interested in learning more, below is some information on some of the most widely used rating systems, with corresponding links.

Leadership in Energy and Environmental Design (LEED)
LEED is the oldest rating system currently in wide use in the United States, developed by the United States Green Building Council in 1993, with the first projects certified in 1998. Both commercial and residential buildings -- and, more recently, whole neighborhoods -- are measured against qualifications for sustainability. LEED is a third-party certification system based on a points earned for a variety of sustainability features including energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, and stewardship of resources and sensitivity to their impacts. For more information, visit:

Energy Star
Energy Star is a joint program from the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE) that creates guidelines to help consumers conserve energy and save money. Initially, Energy Star was a label applied only to products, namely major appliances and electronics. However, it has extended its coverage to newly constructed homes and commercial buildings. For more information, visit:

National Green Building Standard
The National Association of Home Builders (NAHB), through the NAHB Research Center, developed these guidelines with the International Code Council as a means to assist homeowners who want to include green features in their homes. Although it is targeted primarily to single-family homes, it is based on similar criteria as LEED, with the added focus on homeowner education on the maintenance of green buildings. For more information, visit:

Home Energy Rating Systems (HERS)
Published by the U.S. Department of Energy, the HERS programs provide energy efficiency guidelines, as well as recommendations for improvements. The requirements measure both existing and new homes, gauging how well federal standards are met.
The Northeast Home Energy Rating System (NEHERS) Alliance was formed in 1998 to coordinate and promote HERS programs in the Northeast. More information on them can be found at
The National Association of State Energy Officials and Energy Rated Homes of America founded the Residential Energy Services Network (RESNET) in 1995 to develop a national market for home energy rating systems and energy efficient mortgages, which are a significant part of the HERS program. For more on RESNET, HERS, and to find HERS-certified raters, visit:

National Center for Healthy Housing
This organization recently did a study that analyzed whether or not a "green" home was considered a healthy home. By evaluating common rating systems, it concluded that a green home does not necessarily constitute a healthy home. To promote homes that are both healthy and sustainable, the NCHH has developed their own action steps, in addition to providing resources that help homeowners stay aware of the differences. For more information, visit:

Last updated June 12, 2018