Begun during the height of the 2008 financial crisis, One Bloor East's design was a major step toward the supertall buildings now in development along Bloor Street.

One Bloor East is one of the first major examples of a pile-supported raft foundation in Toronto, with dramatic results - when it was completed in 2016, One Bloor East stood twice as tall as its existing neighbours. The soft soils in this area slowed high-rise developments on Bloor until the 1960s, and those that were built rarely exceeded 40 floors. The raft foundation evenly redistributes structural loads across the tower's footprint, and rests on caissons extending into bedrock to control settlement. This foundation design keeps the building structurally independent of the TTC Line 1 subway tunnel only 11 metres away.

The structure of the tower itself is simpler than the building's appearance suggests - each floor's basic layout is the same, except for the balconies that give the tower its shifting, undulating look. Walls around the central elevator core on each floor create a 'core within a core' that functions as a bracing spine for the entire height of the building - this core is centred over the caissons beneath the raft foundation for increased stability. A Tuned Liquid Sloshing Damper (TLSD) on the upper mechanical level (78th floor) uses a water tank to counteract movement from wind forces.

Originally set to have 65 occupied floors, 10 more floors were added to the building design as Canada recovered from the financial crisis and condo sales rose. With the pile-supported raft foundation and the simple floor layout for the tower, only minor changes were necessary to incorporate these additional floors into the structural design.