[5] In September 2014, the developers filed plans for a 65-story, 679 feet (207 m) tall mixed-use tower named 420 Albee Square, designed by SLCE Architects.

However, by November 2015 these plans had been scrapped in favor of a shorter 35-story tower featuring 500,000 square feet (46,000 m2) of office space.

[10] Otera Capital, a Canadian real estate lending company, provided a $235 million construction loan for the project in July 2018.

[1] Because of an existing hotel and apartment tower built around the perimeter of the site, One Willoughby Square will have an irregular T-shaped floor plan.

Additionally, the mechanicals, elevators and bathrooms of the building will be offset to the side of the tower (rather than its center) to reduce the amount of interior walls and maximize open floor space.