To achieve the carbon reductions needed to prevent a global ecological catastrophe, almost every house in North America will need a deep-energy retrofit. If the projecting elements on a home’s exterior — especially the eave and rake overhangs — can be stripped away, the best retrofit option is to wrap the exterior of the house with an airtight membrane and a deep layer of insulation, followed by new siding, roofing, and windows.
Because the purest version of this insulation technique requires a building’s roof overhangs to be lopped off, the method is referred to as a “chainsaw retrofit.”
The chainsaw retrofit technique has a precise point of origin. The method was pioneered by two Canadian energy researchers, Rob Dumont and Harold Orr, who cut off the eaves and rakes of a modest ranch house at 31 Deborah Crescent in Saskatoon in the summer of 1982. The work was funded by the Institute for Research in Construction, a branch of the National Research Council Canada.
Dumont and Orr are both retired. As the first generation of building scientists and residential energy researchers gets old enough to pass the baton to younger practitioners, it’s important to remind today’s young architects and builders of their ground-breaking work.
Dumont and Orr were key members of the research team that designed the Saskatchewan Conservation house in 1977. Five years later, the two engineers set about to develop a technique for superinsulating existing homes.
In retrospect, it’s clear that Dumont and Orr were the first to combine a number of elements that have become part of the standard procedure for deep-energy retrofits. The work at 31 Deborah Crescent included the following steps:
In August 1982, the retrofit work began on the 1,200-square-foot house at 31 Deborah Crescent, described by the researchers as “a bungalow built in 1968.”…