The Agency for Natural Resources and Energy (ANRE) under the Ministry of Economy, Trade and Industry (METI) reviewed the definition of Net Zero Energy Houses (ZEHs), an effort to achieve net zero energy consumption in residential houses, and included the introduction of stationary storage batteries in the essential facility requirements for detached houses.

The new definitions are named GX ZEH for detached houses and GX ZEH-M for collective housing, which are chosen with consideration to be distinguishable, while following the current names, ZEH and ZEH-M. The new definitions will be applied from April 2027 onward.