“For those concerned with climate change and other environmental impacts, reusing an existing building and upgrading it to maximum efficiency is almost always the best option regardless of building type and climate,” according to the findings of a building research study by Preservation Green Lab. Released in January, 2012, the report is the most comprehensive study to date of the environmental impacts of new construction versus renovation and retrofitting. It found that no matter how energy efficient a new building may be, it typically takes many decades to overcome the environmental costs of demolition and new construction. Read the report.