Sagan is a graduate of the Yale School of Architecture. Sagan is an advocate for green building throughout New England; he has served on the board of the Northeast Sustainable Energy Association and he is one of the original authors and active members of the Vermont Builds Greener standards. Sagan is co-founder with Alisa Dworsky of Terra Firma, Inc., a design/build firm specializing in the design and construction of super energy-efficient, renewably-resourced, climatically derived homes. Sagan teaches Active Building Systems 1 (which focuses on HVAC), Design Studio, and Design/Build.