The older housing stock in the U.S. has been receiving energy-related upgrades over the last decade.
According to the Harvard Joint Center for Housing Studies, homes built before 1980 are now better insulated and have newer windows and heating equipment compared to 2009. For instance, 20 percent of older homes were considered “poorly insulated” in 2009, compared to 17 percent in 2015.
Of course, newer homes are even more efficient. Only 8 percent of homes built between 1980 and 2009 are deemed “poorly insulated,” and 78 percent have double or triple pane windows.
As for new construction, which are homes built after 2009, 89 percent have double or triple pane windows, and only 1 percent are poorly insulated.