Each year in the U.S., approximately 1.7 billion square feet of buildings are demolished and approximately 5 billion square feet of newly constructed buildings are added to the total building stock. Until recently, the environmental impacts of this cycle of demolition and new construction have been poorly understood, as were the opportunities to gain carbon savings through building retrofit and reuse.

Earlier this year, the National Trust for Historic Preservation released "The Greenest Building: Quantifying the Environmental Value of Building Reuse," the most comprehensive analysis to date comparing the environmental impacts of new construction compared to retrofit and reuse of existing buildings. Commissioned by Preservation Green Lab, a project of the National Trust for Historic Preservation, the study found that building reuse typically offers greater environmental savings than demolition and new construction and that building reuse and retrofits substantially reduce climate change impacts.

Patrice Frey from the National Trust for Historic Preservation provided an overview of the study's findings and discussed how the study's data and methodology can be applied to the work of planning professionals.