This documents outlines the decision to reclad:
https://cintec.com/wp-content/uploads/2018/01/CCE-Article-WSP-November-2017.pdf
I didn't realize this is Hudson's Bay HQ.
Excerpt:
The Challenge: Deteriorating Precast Cladding In 2013, the owners engaged WSP to perform a condition assessment of the precast cladding of The Simpson Tower, now referred to as 401 Bay. Following an extensive study, several management strategies for the precast cladding were presented ranging from restoration as a minimum, to the extreme case of overcladding or recladding. The latter options were intended to renew the façade and minimize maintenance and repair of the existing cladding. A significant concern for the client in addition to life-cycle costs was the impact on building operation and occupants.
The Solution: Overcladding After reviewing the cost/risk implications of each option and considering impact to existing tenants, the owners chose to overclad. By externally securing the precast panels and installing new cladding outboard of the existing cladding, minimal interior work would be necessary providing less impact to the existing tenants. Renewing the façade by overcladding the building with a new curtain wall system also provided the owners with several positive impacts by: Renewing the overall life of the exterior envelope Updating the architectural look of the building using more modern materials and technologies; Greatly improving the thermal performance of the building, which in turn saves on energy costs; and, Upgrading the building to allow the owners to attract and maintain high quality tenants
By using this innovative approach, the project is moving along successfully without significant tenant disruption that would occur with an alternative re-cladding approach.