As of late October 2023, Energy Star tightened its standards for certification. For example, under the new Energy Star criteria, U-factors must be no higher than 0.22 in the Northern Zone (encompassing most of the upper half of the country) and no higher than 0.32 in the Southern Zone (encompassing Florida and southernmost areas of Alabama, Louisiana, Texas, Arizona, and California). The new criteria for the Solar Heat Gain Coefficient was adjusted to no less than 0.17 in the Northern Zone and no more than 0.23 for the Southern Zone.