The Sustainability Institute at UNH collaborates with a number of regional, national, and international higher education institutions and organizations around sustainability.

• Association for the Advancement of Sustainability in Higher Education (AASHE): UNH has a member of AASHE since 2006, including being a pilot and charter member of STARS. UNH Chief Sustainability Officer Tom Kelly is on the AASHE Advisory Council and is involved in AASHE's Education for Sustainability (EfS) efforts, and UNHSI Associate Director Sara Cleaves is a STARS Technical Advisor.
• Northeast Campus Sustainability Consortium (NECSC): UNH is a founding member of the Northeast Campus Sustainability Consortium (NECSC). The first NECSC was hosted at UNH in 2004. Designed to convene the growing network of higher education institutions, non-profits, activists, and community members working to advance campus sustainability in the northeast region and to represent a growing network of institutions of higher education from the northeast United States and Eastern Canadian Provinces, NECSC and its annual summits are part of the United Nations Decade of Education for Sustainable Development, which began in 2005. An annual summit will be held through 2014 and rotates locations throughout the region. The 2005 summit was held at Harvard University, the 2006 summit at Yale University, the 2007 summit at Bowdoin College, the 2008 summit at Princeton University, the 2009 summit at the University of Vermont, and the 2010 summit at McGill University. The final 2014 summit will return to New Hampshire. 
• American College & University Presidents Climate Commitment (ACUPCC): UNH was the first land grant university in New England to sign the American College & University Presidents Climate Commitment in 2007. UNH collaborated with Clean Air - Cool Planet to develop the first greenhouse gas emissions "calculator" for colleges and universities, now being used by the ACUPCC and thousands of campuses in North America.
• UNH is also a signatory to the Talloires Declaration.