The Barr Foundation, one of the New England region’s largest private philanthropies, has largely been a family-run affair since its creation in 1997. Now, that is changing.

The foundation’s three-member board of trustees, including its billionaire founders, Barbara and Amos Hostetter, will add two new members, M. Lee Pelton, president of Emerson College, and Susan Tierney, a senior adviser at Analysis Group and an expert on energy markets and environmental regulation.

“We have recognized the importance of expanding governance beyond the founding family,’’ Barr cofounder and chairwoman Barbara W. Hostetter said in a statement Tuesday. “At a time when the challenges and urgency of progress are greater than ever, we look forward to this step in broadening Barr’s governance.’’

The new board members will join the Hostetters and the only other non-family board member, Barr Foundation president Jim Canales, in directing the organization’s grant making.

The private foundation, created from the fortune Amos Hostetter amassed as the cofounder of Continental Cablevision, is now worth $1.7 billion.

It will distribute about $80 million in grants to charitable causes this year.

Megan Woolhouse

The expansion of the board comes as the foundation seeks to increase its visibility and ­influence broadly in the areas of climate change, the arts, and education. A $1.7 million grant last year to The Trustees of Reservations last year, for example, helped the group investigate plans for a major new park along the Boston waterfront that would provide public access to the harbor and help create a buffer against rising sea levels.

Pelton and Tierney both hold doctorates in their respective fields and were chosen for the expertise “in and beyond Barr’s focus areas,’’ the foundation said.

“It’s a huge step for us,’’ said Barr Foundation president Jim Canales, who became the first non-family board member when he took the job in 2014. “To Barbara and Amos’s credit, they want to transition Barr from a family to a legacy foundation.’’

Pelton has been president of Emerson since 2011, and his resume includes a stint teaching English and American literature at Harvard University, where he earned his doctorate. For 13 years, he was president of Willamette University in Salem, Ore., and he often speaks and writes about the value of liberal education and importance of leadership development, civic engagement, and diversity in higher education.

Tierney is an expert on energy policy and economics, specializing in the electric and gas industries. She holds a doctorate in regional planning and public policy from Cornell University and has consulted broadly on energy markets, as well as economic and environmental regulation and strategy. She served as commissioner of the Department of Public Utilities under former Governor Michael Dukakis, secretary of environmental affairs under former Governor William Weld, and as the Clinton administration’s assistant secretary for policy at the Department of Energy.

Meg Woolhouse can be reached at megan.woolhouse @globe.com. Follow her on Twitter @megwoolhouse.