New evidence shows that "embodied energy" of a building (the work and materials that went into building it) is far greater than the energy that is saved over years of a newer building.
Also, writes John McKinney, older buildings are often already energy-efficient:
"U.S. Department of Energy research on the energy performance of existing buildings ascertained that commercial buildings constructed before 1920 use less energy per square foot than buildings from any other period of time except after 2000. Older buildings, it seems, were constructed with high thermal mass, passive heating and cooling. And, obviously, were built to last."