SECTION 1. Section 2 of chapter 772 of the acts of 1975 is hereby amended by striking out the definition of “Landmark” and inserting in place thereof the following definition:-

“Landmark”, any physical feature or improvement designated by the commission in accordance with section 4 as a physical feature or improvement that, in whole or in part, has historical, social, cultural, architectural or aesthetic significance to the city, the commonwealth, the New England region or the nation.

SECTION 2. Notwithstanding any general or special law, rule or regulation to the contrary, this act shall only apply to the Boston Landmarks Commission; provided, however, that the designation of a landmark based on significance solely to the city of Boston shall not apply to any property where, on the effective date of this act, building permits approved by the city of Boston or zoning variances granted by the zoning board of appeals in the city of Boston are in effect and unexpired; provided further, that said building permits or zoning variances remain in effect and unexpired; provided further, that this act shall not apply to any portion of a property within a planned development area zoning overlay district approved by the city of Boston zoning commission on or before the effective date of this act where a building permit has been approved by the city of Boston during the 2 years following the effective date of this act; and provided further, that said building permit remains in effect and unexpired.

SECTION 3. This act shall take effect on July 1, 2023.

SECTION 4. In the case of a property within a planned development area zoning overlay district approved by the city of Boston zoning commission on or before the effective date of this act, this act shall take effect on July 1, 2025.