According to The Greenest building: Quantifying the Environmental Value of Building Reuse, renovating an existing historic office building in Chicago reduces the building’s impact on climate change by up to 12 percent when compared to constructing a new building. Results vary by climatic zone, so refitting an office building in Portland, Ore., reduces that impact by up to 16 percent, the report said.
This impact on climate change versus a new “green” building is due to the immense amount of carbon expended – on things such as new materials and transportation of said materials – at the start of a new building project. The report says that it can take between 10 to 80 years for a new energy-efficient building to overcome, through efficient operations, the climate change impacts created by its construction.
Scale matters, so much so, that retrofitting, rather than demolishing and replacing, just 1 percent of the city of Portland’s office buildings and single family homes over the next ten years would help to meet 15 percent of their county’s total CO2 reduction targets over the next decade, the report says.
In December, the Minnesota Department of Commerce announced retrofit projects across 36 facilities that it says will generate more than $3 million in permanent, ongoing energy savings every year for the foreseeable future.
The improvements targeted commercial, industrial, and nonprofit facilities across the state. Such facilities account for half of the state’s energy use, and retrofitting offered the Commerce Department what it called the “biggest bang for our buck.”