YC Condominiums is a very slender 63-storey, 200m tall residential tower that includes three levels of retail, two-levels of office space and five-levels of below grade parking. Because of its slender profile, frequent lateral wind motions which can cause occupant discomfort were a crucial design criteria. Adding to this project’s complexity, the developer’s mandate to maximize sellable space within a prescribed zoning envelope required a novel supplemental damping system design which did not occupy sellable space. The result is the implementation of an exceptionally efficient structural and damping configuration. The project is the first in the world to employ the patented viscoelastic coupling damper system, which utilizes high damping 3M viscoelastic (VE) material in a unique configuration. Along with achieving the directive of optimal square footage, this configuration has the added benefits of increased flexibility in suite layouts and minimizes the number of coupling beams crossing over the corridor (less mechanical coordination).