Deep energy retrofits are a vital part of our efforts to decarbonize buildings. Within the United States, approximately 80% of existing buildings are expected to still be in use in 2050. Unfortunately, the vast majority of those buildings were designed and built at a time when fossil fuels were dirt cheap and strategies for energy conservation were considered a waste of money or (at best) foolishly supererogatory.

Through deep energy retrofits, we can make these building more efficient, comfortable, and durable, but it will take more than just elbow grease. We will also have to develop multiple strategies because there is no one-size-fits-all approach that can be used on, say, a single-family home in Arizona dating back to 1982 and a three-decker in Worcester built in the 1890s. Learning from the unique experiences of others as they work on buildings from across the decades and within different climate zones can be vital for learning about the potential pitfalls they've encountered and the potential solutions they've devised.