The Northeast Sustainable Energy Association (NESEA) is a membership-based professional trade association that promotes energy efficiency and renewable energy solutions throughout 10 Northeastern states: Connecticut, Delaware, Massachusetts, Maine, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. NESEA conducts professional development trainings, organizes the largest regional building energy conference and trade show, and operates regional energy programs.
NESEA's annual Green Buildings Open House (GBOH) is the largest sustainable energy event in the Northeastern USA. It is held annually on the first Saturday of October in conjunction with the American Solar Energy Society's National Solar Tour. Its goal is to showcase the energy efficiency and renewable energy features in the many advanced buildings within NESEA's 10-state territory. It connects consumers with professionals who can provide the services and products needed to retrofit current buildings and build new buildings capable of deep energy reductions and the on-site generation of clean power.