Energy Retrofits in Historic Homes. Stephanie Horowitz was enlisted by Boston Globe staff to tour a historic Somerville home and share her thoughts about how to improve its energy efficiency towards net-zero performance. Stephanie joined air-sealing specialist Jason Taylor of Byggmeister Associates and contractor Mark Philben of Charlie Allen Renovations on the tour. The group provided recommendations on the attic and basement insulation, use of a blower door test for checking air leaks, proper interior and exterior wall insulation, custom-built storm windows, and more. The piece provides convenient cost information for each topic, giving the reader a sense of what a retrofit to an old home might set them back. The question remains - if net-zero is your goal, is retrofitting an old home the most reasonable path?