The commercial buildings involved in the study were assessed over a 30-year period. These buildings included schools, small and midsize office buildings, midrise apartments, and stand-alone retail. The results in the commercial sector were just as impressive. Primary schools would see an energy reduction of 9% on average, with secondary schools showing 7%. Upgrading the roof and pipe insulation in only 25% of commercial buildings in the US would save more than 700 therms of natural gas per year. That is the equivalent of having 800,000 fewer gasoline powered vehicles on the road. CO2 emissions savings would near 360 million metric tons, or the equivalent use of more than 45 million American households.
Lastly for the residential portion of the study they were assessed over a 50-year span after code-compliant retrofit implementation. The savings results would have a positive impact in any household. Energy savings would be 10 to 45% in homes that are air sealed and add floor and ceiling insulation. In most cases, wall insulation was already in place, with the floor and ceiling being neglected during the building process. These retrofits would cause a reduction in carbon emissions of roughly 10 billion tons over the study period. That is equivalent to the annual energy use of over 1 billion homes or operating almost 3 million wind turbines over a year.
Source: Insulation Outlook article titled Insulation Upgrades Save Energy and Emissions in Existing Buildings
