A great number of historic masonry buildings exist across North America, and today they are being re-imagined with an endless variety of uses. Renovating and reoccupying these old buildings is rightly considered an act of sustainability in itself. Using the existing structure can mean 50% to 75% less embodied carbon, on day one of occupancy, than a new building would generate.
In the 21st century, our existing masonry buildings also need to be made as energy efficient as possible to help fight climate change. Their operational energy use should be reduced to Passive House levels that can result in net zero emissions. This can be done safely and robustly, so there is no excuse for historic masonry buildings to not aggressively address efficiency.