Historic buildings have embodied energy in them that is lost if a building is demolished. Embodied energy is a measurement of energy used in the process of building, from the extraction of raw materials - such as harvesting trees - to the final installation of the finished material - such as framing lumber and carpentry. For example, if a new 50,000 square foot commercial building were built to replace the Church, on average the new building would embody 80 billion BTU, the equivalent of 576,784 gallons of diesel fuel, enough to power 1534 loaded tractor trailers from New York to LA.
Over their lifespan, historic buildings illustrate one of the best sustainable characteristics: durability and reparability. Durable buildings require less embodied energy to maintain and repair. Old buildings are often easier to maintain and repair due to lower technology, high craftsmanship, and better quality materials such as stone and wood.
In addition, demolition and waste have profound adverse impacts on our landfills. A recent University of Washington Study reports that building-related construction and demolition debris constitute about two-thirds of all non-industrial solid waste generation in the United States. When we reuse our historic buildings rather than replacing them, less debris ends up in landfills and our environment is healthier. Recycling materials is often suggested as a positive outcome from building demolition. However, recycling demolition waste is energy-intensive and expensive.
Many people believe that old buildings always have higher utility costs and thereby waste energy. While this is often true for old buildings built after 1940, it is not usually true for even older buildings. In fact, data from the U.S. Department of Energy indicates that commercial buildings constructed before 1920 actually use less energy per square foot than buildings from any other decade up until 2000. This is because they were designed before an era that relied on mechanical heating, cooling and shading devices, and they utilized simple design solutions that kept human occupancy and comfort levels high. These buildings were designed to take advantage of natural daylight, ventilation, and solar orientation - the very characteristics that are being employed as “sustainable” design attributes today. According to a study by the U.S. Energy Information Administration, our older commercial building stock - pre-1920 - performs at an average of 80,127 BTU/sf while new green buildings from 2003 perform at 79,703 BTU/sf.
It's ironic that in Saskatoon, while we may obsessively recycle our cans and papers, we often turn our backs on opportunities to achieve much greater environmental benefits by recycling our massive buildings.