Establishing minimum energy efficiency levels in new homes and buildings, building energy codes have been a cornerstone of energy efficiency policy in the US since the 1970s. …In recent decades, energy codes have steadily reduced energy demand from homes and buildings by 50% or more. …Despite that impact, these commonsense construction standards that were once bipartisan are now under unprecedented attack around the country. A series of recent and pending policy shifts could sharply reduce the ability of codes to deliver savings from energy efficiency gains moving forward. …Despite decades of similar findings by federal scientists and economists, some of the biggest threats to codes are coming from the federal government. …In late April, the Department of Housing and Urban Development and the rescinded a statutorily required update to the energy code covering most of its housing programs. …In addition, there is turbulence at the residential-code-making organization itself.