CHICAGO (WLS) — In a significant upgrade for the iconic former John Hancock building, 360 Chicago embarked on a project this Wednesday to install new windows on its upper levels.

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The task of swapping out each of the original windowpanes, which the building has retained since its inception, is a meticulous process, taking approximately an hour for each of the over 200 units.

Following last year’s announcement about the closure of the Signature Room restaurant on the 95th floor, plans were set in motion to extend the 94th floor, aiming to establish Chicago’s first two-story observation deck.

Standing at 5 feet by 8 feet and weighing around 350 pounds each, the new window installations mark a substantial enhancement.

Overseeing this pivotal transformation is Christopher Glass & Aluminum, a trusted local firm based in Chicago.

The newly fitted windows feature double-pane, low-iron glass, a choice that promises to enhance thermal regulation, boost energy efficiency, and offer an exceptionally clear view of the cityscape.

“The original glass let in less than half of the natural light that you’re now seeing and had much more internal reflection. The new glass significantly increases the brightness while also reducing the glare, so that our guests will experience Chicago skyline in a much more vivid way,” Managing Director at 360 Chicago Nichole Benolken said.

“The whole point of this experience and coming up and enjoying yourself with your family friends was to take pictures, right, to enjoy the space, whether it’s daytime, nighttime, and with this glass, you’re able to meet that goal,” Christopher Glass & Aluminum Director of Sales said.

The new observation deck is expected to be open to customers by mid-2027.