[Important] Standard compliance is mandatory for all new buildings from April 2025.

With the enforcement of the revised law on April 1, 2025, in principle, all newly built houses and non-new houses will be obliged to comply with energy conservation.
Please confirm homepage (outside site) of Ministry of Land, Infrastructure, Transport and Tourism for the details of law revision.

With the expansion of the above-mentioned standard compliance obligations, notification obligations (Article 19) will be abolished.
In addition, "Notes on the application of rules before and after the enforcement date of the Revised Building Standards Law and the Revised Building Energy Conservation Law" (May 30, 2024 Kunizumi finger No. 99, Kunizumi Sanden No. 791) (PDF: 155KB), notification and explanation based on the Building Energy Conservation Law before the revision pertaining to buildings started after the enforcement date are not required, so please check together.

For the handling before and after the enforcement date, "Notes on the application of rules before and after the enforcement date of the revised Building Standards Law and the revised Building Energy Conservation Law" (May 30, 2024, Kunizumi No. 99, Kunisumi Building No. 791) (PDF: 155KB).
In particular, please note that the construction of buildings that start construction after the enforcement date is subject to compliance obligations.