We often have many questions associated with retrofitting versus new construction. Which option is better? What if a new structure has low operational emissions? What if we offset operational energy with renewable energy? We can answer many such questions by conducting a high-level carbon emissions assessment using the CARE Tool, which calculates the operational and embodied carbon emissions of reusing, upgrading or replacing an existing building.
We recently utilized CARE to evaluate the Horace Mann Building at Salem State University using the following inputs:
Assuming all the operational emissions are offset by renewable energy and the building is net zero, we can minimize the emissions to only embodied carbon, which can be compared.
Finally, after comparing all aspects, we concluded that retrofitting is the best way to minimize the overall carbon emissions for the Horace Mann Building. In a typical retrofitting project, we reuse the most carbon-intensive components of a building including structure and foundation, thus significantly reducing embodied carbon and operational carbon. In addition, by retrofitting with a high-performing envelope, and energy-efficient mechanical systems we can further reduce the carbon emissions. Utilizing the CARE Tool early in the design phase enables us to determine the best approach for reducing carbon emissions for building reuse versus displacement.