Tishman Speyer will start construction on its signature project on Manhattan's Far West Side in June, the developer announced Tuesday, after finalizing its anchor lease and a massive construction loan.

The developer, which owns Rockefeller Center and the Chrysler Building, will finance the $3.7B Spiral tower with $1.9B in equity and a $1.8B construction loan from Blackstone Mortgage Trust. Tishman Speyer and a group of pension, foreign and institutional funds all contributed equity in the deal.

The tower is expected to take four years to build, and Pfizer has agreed to move its headquarters there on a 20-year lease when it opens in 2022.

The tower, with an address of 66 Hudson Blvd., will sit astride the High Line, New York's renowned elevated trail park, and the 4-acre Hudson Boulevard Park. Designed by Danish architect Bjarke Ingels, the tower's distinguishing element is a connected outdoor terrace, complete with hanging gardens, that circles the building from bottom to top. The spiraling feature is meant to be a vertical continuation of the High Line, which ends at the tower's base.

Pfizer will occupy 800K SF on floors seven through 21 in the 65-story office tower, which will have 25K SF of retail at its base. It is moving from its two-building, 1.1M SF headquarters on 42nd Street, which it marketed for sale in early 2017. It reached a deal to sell the properties to David Werner for $360M as it was finalizing its Spiral lease, The Real Deal reports.

The properties fall in the Midtown East rezoning district, but Werner has not revealed his ultimate plan for the soon-to-be-vacated properties. While JPMorgan Chase is the first company to take advantage of the new zoning law, few expect many other property owners to follow suit in the near term.