Demolition and construction of a new building. In the HARB Overlay District only, whenever an existing building is demolished in whole or in part, and a new building (or portion thereof) is erected in its place, no new off-street parking spaces shall be required; provided, however, that if the use of the new building in the HARB Overlay District provides five or more dwelling units, off-street parking shall be provided for each dwelling unit in accordance with the applicable criteria. In the portions of the Town Center District which are not included in the HARB Overlay District, if an existing building is demolished in whole or in part and a new building (or portion thereof) is erected in its place, off-street parking shall be provided for the new building or part thereof in accordance with the applicable criteria.