This Act comes into effect on April 1, 2026; provided, however, that the provisions set forth in the following items come into effect on the dates specified respectively in those items:

①The provisions of the Act on Building Unit Ownership as amended by Article 1 (hereinafter referred to as the "new Building Unit Ownership Act" in this Article and Article 5, paragraph (7) of the Supplementary Provisions) also apply to matters that arose before this Act comes into effect, except as otherwise provided for in these Supplementary Provisions; provided, however, that this does not prejudice any effect that has arisen under the provisions of the Act on Building Unit Ownership prior to the amendment by Article 1 (hereinafter referred to as the "former Building Unit Ownership Act" in this Article).

②The provisions then in force continue to govern a meeting for which the convocation procedures commenced under the provisions of the former Building Unit Ownership Act before the date on which this Act comes into effect (hereinafter referred to as "the effective date").

③Any matter provided for in bylaws under the provisions of the former Building Unit Ownership Act that are in effect at the time this Act comes into effect, and that conflicts with the new Building Unit Ownership Act, ceases to be effective on the effective date.

④The provisions of Chapter III of the new Building Unit Ownership Act do not apply to a building destroyed before the effective date; provided, however, that this does not apply to a building destroyed by a disaster specified by the Cabinet Order referred to in Article 2 of the Act on Special Measures Concerning the Reconstruction, etc. of Buildings under Unit Ownership Damaged by Disasters as amended by Article 2, in the case where that Cabinet Order has come into effect on or after the effective date.

The provisions then in force continue to govern the application of penal provisions to acts committed before the effective date.

Around five years after this Act comes into effect, the Government is to consider the development of a system capable of appropriately responding to consultations from managers, unit owners (meaning unit owners as prescribed in Article 2, paragraph (2) of the Act on Building Unit Ownership as amended by this Act; hereinafter the same applies in this paragraph), or persons who were unit owners, and other measures for the prevention and resolution of disputes concerning the repair, etc. of the common areas of condominiums, etc. to which the provisions of that Act apply, taking into consideration the state of the establishment or amendment of bylaws concerning manifestations of intention to the contrary, etc. referred to in Article 26, paragraph (2) of that Act, the state of claims for and the receipt of insurance money, etc. prescribed in that paragraph, and other circumstances, and if it finds it necessary, is to take the required measures based on the results.

Beyond what is provided for in these Supplementary Provisions, the transitional measures necessary in connection with the enforcement of this Act (including transitional measures concerning penal provisions) are specified by Cabinet Order.