Jonathan Kantar, Principal of Sage Builders LLC, has over 30 years of experience in residential design and construction, real estate development, project management, and consulting. Jonathan’s industry-leading focus on energy use reduction includes the renovation and construction of homes under the Energy Star, LEED and Deep Energy Retrofit (DER) protocols.

A Newton, MA native and resident, Jonathan is a member of Newton's Design Review Committee and Energy Commission. He is a board member of Historic Newton, former chair of Newton’s High-Performance Buildings Coalition, and an active volunteer in a wide variety of community projects and programs that promote sustainable building and energy efficiency practices. Jonathan serves on the Governor's Zero Net Energy Buildings Advisory Council. He holds a B.A. from the University of Michigan and a Master’s in Sustainable Design and Construction from the Boston Architectural College.