New York City put a high price on approving plans for a Kohn Pedersen Fox–designed supertall tower in Midtown Manhattan. Under an agreement with the de Blasio administration, the project’s developer, SL Green, will only be granted a special permit to build One Vanderbilt—a 1,414-foot-tall tower (1,514 with the spire) adjacent to Grand Central Terminal—if it makes much-needed improvements at the iconic rail station next door.

Improving circulation at the already congested station will not be an easy task for SL Green. More than 700,000 people pass through Grand Central every day and thousands more are scheduled to arrive when the Long Island Rail Road connects to the station in 2023. On top of that, SL Green hopes to fill One Vanderbilt with 8,000 workers, many of who will commute to the office by train.

In mid-October, SL Green unveiled a detailed breakdown of its $210 million plan to address these challenges. At street-level, the developer carves out 4,000 square feet from One Vanderbilt to create a glassy waiting hall that comes with a living green wall. This space connects below-grade to the station, and at-grade to a new block-long public plaza along Vanderbilt.

While these public realm improvements are the most visible components of the plan, they represent only a fraction of the overall cost. The majority of SL Green’s proposal (over $139 million) goes toward improving the subway station underneath Grand Central where the 4,5,6, and 7 lines connect. Specifically, this includes improving circulation at an existing mezzanine, building a new staircase to the Grand Hyatt Hotel, making platform modifications, and creating new stairways and passageways throughout the terminal. SL Green would also invest over $30 million to improve the Grand Central-Times Square shuttle train and to accommodate the station’s future Long Island Rail Road service.

On October 20, shortly after SL Green presented its plan, the City Planning Commission certified the larger Vanderbilt Corridor rezoning, which includes One Vanderbilt. The certification kicked off a months-long public review process.

“The proposed zoning change for the Vanderbilt Corridor is Phase One of our efforts to ensure a vibrant and productive future for East Midtown, which is something that the business community, the local community, and indeed the entire city desires and needs,” said City Planning Commissioner Carl Weisbrod in a statement. “Consistent with our approach to planning under this administration, this proposed zoning coordinates new development with appropriate infrastructure and services by requiring the developers of major new buildings to provide specific and significant public transit and public realm improvements.”

While local residents have been quite skeptical of SL Green’s plans, the developer’s detailed report addressed many of their concerns. “At our last meeting, we asked SL Green for specifics and transparency regarding the estimated costs of the public improvements,” said Vikki Barbero, the chair of Manhattan’s Community Board 5, in a statement. “Today, they came through with a detailed report and an in-person meeting with the leadership of SL Green, during which they attentively answered every question we posed. There is still much to consider, as we continue to evaluate this proposal, but we are deeply appreciative of the good working relationship SL Green has now worked to establish with the Task Force and CB5.”

SL Green expects to finish ULURP by April or May and have the transit upgrades and tower completed by 2021.