Construction work has begun on Foster + Partners' delayed New York tower at 425 Park Avenue (+ slideshow).

Originally planned for the Lehman Brothers bank, whose collapse helped trigger the financial crisis in 2008, the Foster-designed skyscraper is back on schedule and will be the first new office tower on Park Avenue in 50 years.

Construction work began on the delayed project yesterday, after developers L&L Holdings and GreenOak lined up financing to restart the project, and it is due to be completed in 2018.

Foster + Partners beat Rogers Sirk Harbour + Partners, OMA, and Zaha Hadid Architects in an invited competition for the tower nearly three years ago. At the time, the Lehman Brothers' estate still controlled more than $10 billion of real estate assets, despite the bank having declared bankruptcy four years earlier. The estate is no longer involved with the project.

Earlier this week, Foster's long-rumoured ousting from the World Trade Centre site was confirmed when Bjarke Ingels' firm revealed its skyscraper for 2 World Trade Centre, replacing the British firm's previous design.

Although the 425 Park Line site is less prominent, the developers and the architect hope the building's distinctive three-part design will help to revive an office district defined by ageing midcentury buildings.

Home to SOM's Gordon Bunshaft-designed Lever House and Mies van der Rohe's Seagram Building, the midtown section of Park Avenue was once the city's premier office district, but has been edged out by Midtown West and a resurgent Downtown over the last twenty years.

"The prime location is Park Avenue itself because it is probably unique in the world in terms of being an urban, modernist creation. It has a life, a scale. The first thing that 425 has to do is contribute to that urbanity," said Norman Foster in a statement.

"In the spirit of those individual buildings – that include Seagram and Lever House – 425 has its own identity," he added. "It will contribute to the public domain both at ground level and the wider entity of the city."

At just over 853 feet tall (260 meters), 425 Park Avenue will be far shorter than many of New York's new super-tall skyscrapers. Instead of straining for height, the building is designed with a series of dramatic common spaces and outdoor terraces to capture views of the city.

The new tower will be divided vertically into three sections, with a triple-height atrium at the base that will function as a public gathering space. The base of the building will also have levels that can accommodate trading floors, or large open-plan offices for media companies or creative agencies.

A setback at the second level will create space for an amenity terrace, while a triple-height sky lobby with canted glass walls will offer expansive views of Midtown and Park Avenue, which will be seasonally landscaped and boast a rotating array of sculpture.

The top section will feature another terrace and sky lobby, plus smaller, premium office spaces. Fins running up the building and extending into the sky will give the building added visual impact.

Other towers currently being developed in New York include a 411-metre-tall skinny skyscraper by SHoP Architects, and the MoMA-adjacent 53W53 residential tower by French architect Jean Nouvel.