1. Insulating the house from the outside.

Typically, old homes are insulated by tearing out the interior walls and putting in fiberglass batts, or punching holes in the walls to fill with cellulose or other types of insulation. This home used the “PERSIST” (Pressure Equalized Rain Screen Insulated Structure Technique) insulating system, which involves insulating the house from outside. But because the walls were pushed out, they had to apply for a variance in the permitting process—which was eventually granted, but it did delay the project. The benefit of adding insulation on the outside was that no space was lost on the inside. (In theory, it would also mean that fine plaster walls could be preserved, but they needed to gut them for HVAC and plumbing access.) The result was highly insulated walls, rated at R-40.

3.    Insulating the basement without tearing up the flowerbeds.

A tight house needs to keep heat in the basement from leaking out. Typically in remodels, basement walls are insulated on the inside (which would have lost square footage and would not have been very effective), or a deep wide trench is dug to insulate the foundation (which would have made a huge mess, and there was not much room on the lot to do so). This project used the “Cocoon” method of sucking out a four-inch-wide slice of dirt all the way down to the footings of the foundation, then inserting a one-inch foam sheet and 3 inches of sprayed foam. The net insulating effect is R-30, with very little mess to clean up. (See more about excavation-less insulation retrofits.)

Never Truly Retiring From Teaching

Back in 1978, Stewart Herman wrote Energy Futures: Industry and the New Technology. Now, he is writing articles, has created brochures, and offers free tours and speaking engagements about their home. Why? He told me, “Linda and I intended this house to be a teaching tool for anyone who wants to renovate their home.” As Stewart later wrote in an article for The Cresset, “We had a mission and a message for the wider world. As (retired) teachers, we wanted to demonstrate that an ordinary old house on an ordinary, small, urban lot could be purified of fossil fuel and accommodate all the technology needed to achieve net-zero. More ambitiously, we wanted the house to demonstrate to skeptics that a comfortable lifestyle and environmental sustainability need not clash and that carbon emissions could be lowered drastically without any sacrifice in comfort or convenience. In other words, we thought we weren’t just building for ourselves.” Stewart has loved the process and results so much that he is spreading the word to other aging baby boomers.

Being Part of the Solution

Looking at our homes as part of the solution to our planet’s issues is becoming a trend because, with newer technologies, we can do so much more with our homes. But what is so unique and important about this home is that it is a renovation of an existing house. As the building community is called upon to address climate change, new buildings can more easily be built to being at least net-zero ready. But the existing building stock—to the tune of over 70 million single-family owner-occupied homes in the United States—presents much more of a challenge.  Since most buildings are existing buildings, and they tend to last a long time, renovations are a necessity. For the Hermans, the overall results are quite satisfying. They estimate they offset carbon at a rate of 12 tons per year. Stewart wrote, “We have the daily, delicious experience of feeling that we are part of the solution rather than part of the problem.”