Just beyond the Ed Koch Queensboro Bridge lies the next step forward for the city’s thriving tech sector.

The first phase of the Cornell Tech campus officially opened on Roosevelt Island Wednesday, bringing three environmentally friendly buildings and green space to 820,000 square feet south of the bridge.

Former Mayor Michael Bloomberg, Gov. Andrew Cuomo and Mayor Bill de Blasio applauded Cornell Tech, its transformation of Roosevelt Island and its role in the city’s growing industry. The school — composed of 300 graduate students — has been in the works since 2011, and the leaders said it will help give New York an edge when competing with other cities around the world for top talent.

“It must continue to play a central role to remain a global economic capital,” Bloomberg said of the city during the opening ceremonies. 

For the graduate school’s administrators — and the city, which spearheaded the development — this marks a major leap for New York’s startup industry, which saw a jump of 46,900 jobs between 2010 and 2016, according to a report by the state comptroller’s office.

Daniel Huttenlocher, the school’s dean, said while major tech companies such as Google and Etsy attracted top talent to New York, the city still needed a major academic space for future computer engineers and business leaders.

“Any city that doesn’t become a leader in the tech industry, has a risk of being left behind,” he said.

For the island’s community, which has eagerly watched the complex rise over the past six years, the school promises to inject new life as the added attractions and green space become a destination.

“The buildings look great and I like the landscaping,” said Roosevelt Island resident Damien Sass, 35, as he, his wife and his son recently spent a day enjoying the campus’ great lawn.

“It’s going to be great to have more people come to the island.”

Bloomberg set up a request for proposals to create a new tech college in 2011, and Cornell and its partner, Technion-Israel Institute of Technology, won the bid, beating CUNY, Stanford and other schools.

Three years later, the Ivy League school began demolishing the old Goldwater Memorial Hospital building and commenced construction for the first section of the campus.

The $700 million phase one of the campus includes an academic building (the Emma and Georgina Bloomberg Center), a mixed-use education and startup shared space known as “The Bridge” and a residential tower.

Huttenlocher said Cornell and the architects wanted to give the engineering and MBA students the best facilities, while at the same time respecting the space, which has views of the East Side and Long Island City.

“We wanted to make this a critical mass destination,” he said.

The Bloomberg Center — which stands as a four-story, 160,000-square-foot glass space — serves as the main site for classes. Huttenlocher said Pixar’s offices in California, along with other tech startups, inspired Cornell in the layout and design.

A cafe will be open to students and the public on the ground floor, while the remaining levels have labs, desks and more than 100 meeting rooms. Unlike most college classrooms, or corporate offices, many rooms have glass walls that encourage open collaboration.

The Bridge building continues this theme, but with an emphasis on the vista. The facility is six stories and 230,000 square feet, with glass walls that look out to the Queens and Manhattan skylines.

“Because of the narrowness of Roosevelt Island, the architects looked to take advantage of the river-to-river feeling,” Huttenlocher said.

The Bridge’s focus is startup collaboration. Businesses small and large and researchers are welcomed to lease labs and creative space for their projects and work with students and faculty.

Huttenlocher said about one third of the building has been leased out to companies such as Citigroup and Ferraro chocolate.

While the Bridge and Bloomberg Center are poised to generate major tech ideas, they will be leaving a minimal impact on the environment. On top of the buildings’ roofs is a photovoltaic canopy, containing hundreds of solar panels that will generate most of the power.

Andrew Winters, the school’s senior director of capital projects, who oversaw the development, said the school worked to be as green as possible.

“You’re also saving a lot on the operating costs,” he said.

The green initiatives extend to the two buildings’ heating and cooling systems that are powered by 80 geothermal units buried 400 feet under the campus’ 12-acre south lawn.

While the 270-foot residential tower doesn’t have a solar panel roof, architects worked to make sure it also limited its carbon footprint, according to Winters. In fact, the passive house, which will house about two-thirds of the 300 graduate students, will save 882 tons of CO2 per year.

The students and faculty living in the rooms, which range from studios to three bedrooms, will have a host of amenities, including a rooftop terrace and gym and a gathering space.

Some graduate students, who moved into the campus last month, were impressed with the building.

Jivesh Tolani, 27, who was born in Asia and is studying for his tech MBA, was impressed with the tower’s design and amenities.

“It’s got a view that I don’t think I will ever get again,” he said.

The Cornell student body and faculty won’t be the only ones enjoying the new grounds. The school created more than two acres of open space, including the lawn and plazas between the buildings.

Roosevelt Island community leaders and residents said they welcome the students and faculty to the island and hope that the neighborhood’s transformation will attract more visitors.

James Clynes, chairman of Manhattan Community Board 8, which oversees Roosevelt Island, said even before the buildings went up, young families were flocking to the area. He predicted that the emerging tech companies will also follow suit, further growing the industry’s footprint in the city.

“It’s a classic example of ‘If you build it, they will come,’ ” he said.