However, Prince-Ramus pointed out this was not just a design conceit. The vertical zigzag windows maximize natural light, improve energy performance, and facilitate cleaning.

The cascading windows, with a pop-up modification to the original slant, comply with the American with Disabilities Act and building codes. These requirements were contemplated years after the building's original opening and 1980s makeover.

Buildings now require a minimum height to prevent injuries. Those with visual impairments and using canes could otherwise bump their heads into ceilings or walls, slanting from above, as designed in the original structure.

Although the devil is often in such details, REX's main design drivers were threefold. “First, the existing building had a difficult geometry. Second, part of redesigning the building required us to improve the energy performance of the building,” said Prince-Ramus. “The third was the structure was going to remain occupied during construction.”

On a larger scale, the architecture signified a difference in defining the building and how it would interact with the city.

John Durschinger, senior vice president, global design at Brookfield, also led the tour. “The building is fundamentally different in the way it relates to its context,” he said. “It unlocked Manhattan West and it helped us diversify our position in the market.”

In connecting more with the neighborhood, the dark, foreboding lobby was converted into a lighter, airier space with welcoming places to sit and to socialize. A common theme in developing the Hudson Yards district has been working, living, and playing in the same neighborhood.

Five Manhattan West's ground floor contains 100,000 square feet of retail space. Whole Foods recently announced it signed a lease and will anchor the retail area, with a 60,000 square-foot food destination. Brookfield is talking to other potential retail tenants to lease the remaining 40,000 square feet, and estimates this space to be fully completed by 2020.

The tower's upper floors contain office spaces with floor plans up to 124,000 square feet, 15-feet ceilings, and floor-to-ceiling glass. Prince-Ramus noted these kinds of features well suit tenants in tech, innovation and modern industries. The building's office space is now 99% leased. Amazon recently signed a 360,000 square-foot lease. Other tenants include JP Morgan, R/GA, and Markit.

When Brookfield acquired the property in 2011, the office rents were in the high-30s. Today, they are in the mid-90s. The building had housed the Associated Press since 2004. However, the news and wire service announced in 2015 that it was moving its global headquarters in 2017, and have since relocated to 200 Liberty St.