Renderings of Rockefeller University's planned expansion of its Upper East Side campus that would overhang part of the FDR Drive. Shown, a view of the proposed platform and new buildings seen from Roosevelt Island. Rafael Viñoly Architects

A stretch of the FDR Drive with commanding views of the Queensboro Bridge and the Roosevelt Island Tramway would be dramatically altered under a plan by Rockefeller University to extend its campus over the highway.

Pinched for space, the university long ago filled in the nooks and crannies of its campus, perched on a cliff overlooking the FDR and bordered on the west by York Avenue.

Despite the institution's storied past as the nation's first biomedical research center, campus officials say that some of their facilities are obsolete, and that without a major investment in its real estate, Rockefeller risks falling behind in the race to recruit the best and brightest young scientists. "New talent is our life's blood," said George Candler, the university's associate vice president for planning and construction.

So the university proposed a plan in 2013 to add 160,000 square feet above the highway, including a two-story laboratory, a conference center, an amphitheater and two glass pavilions with offices and a cafeteria. The new buildings would rest on a platform 20 feet above the FDR running roughly between East 64th to East 68th streets, supported by 10 columns along the western edge of the Esplanade, a 3.5-mile pathway between the highway and the East River.

The Esplanade along the East River looking north, with the support columns and platform at the left. Rafael Viñoly Architects

Plans for the project are still wending their way through the city's approval process.

Although the sky would still be clear above the Esplanade, local opponents object to the afternoon shadows that the building will cast on this open space along the river, which is popular with bikers, joggers and dog walkers.

"The Upper East Side is completely starved for open space," said Susan Blackwell, a park volunteer who helps with planting and beautification at the southern edge of the Esplanade.

Some residents complain that the new structure, slated to rise some 80 feet at its highest points above the highway, would cast deep afternoon shadows, putting that section of the pathway in the shade an hour sooner in the early spring and late fall, and as much as 2 hours and 40 minutes earlier at high summer, according to the city-prepared environmental impact statement.

The platform would connect with one of the university's high-rise buildings that already juts out over the FDR Drive at East 64th Street, and with the NewYork-Presbyterian/Weill Cornell Medical Center hospital above the road between East 68th and East 70th streets. It would create a tunnel-like experience for motorists on what was once a scenic portion of the roadway. The university plans to build and maintain lighting for this strip of the drive.

Extending the campus over the drive will allow the university to create "a long, linear building, where laboratories can be quickly reconfigured for different types of research," said Jay Bargmann, a vice president at Raphael Viñoly Architects, which designed the project.

Some also worry that a potential echo effect created by the deck overhanging the highway could amplify traffic noise on the Esplanade, which is already substantial. The university initially proposed building a 5-foot wall separating the Esplanade from the highway, which it said should keep the noise near current levels. Ultimately, it agreed to raise the wall to 8 feet in response to a request from the local community board, which then granted its approval for the project.

The university acquired the air rights to build over the highway from the city in 1973 in exchange for a commitment to make future community improvements. In 1988, it paid $5 million to build a pedestrian bridge to the river at East 63rd Street, which it still maintains today. Rockefeller paid a further $2.2 million in 1993 toward other improvements and maintenance of the Esplanade.

Although those two payments satisfied the university's requirements under the air-rights agreement, Rockefeller has decided to spend $8 million on renovations along the Esplanade in response to an environmental impact statement and the community concerns.

This money, which is in addition to the $240 million plan to expand the campus, will go toward shoring up the sea wall, installing new benches and water fountains, and planting trees and shrubs that can withstand the frequent inundations of salt water. This portion of the pathway is at best 5 feet above sea level at high tide.

The university doesn't plan to add faculty or staff, but expects to move employees from inferior facilities when the new buildings are complete. For example, Rockefeller IT staff members who have worked for years in a temporary tan cloth structure resembling a Quonset hut will eventually move into new permanent offices.

Once they do, the hut will be torn down to make way for a new playground at the 115-child day-care center for the faculty and staff. The plan also includes adding a one-story sports center with rooftop tennis courts on a parking lot in the northwest corner of the campus.

If all goes according to the university's plan, construction will begin next year on the platform, which will be done by lifting the sections over the highway from barges at night. The buildings above the drive would rise by 2017.

The improvements to the Esplanade should take shape in 2018, with the other additions to the campus wrapping up by 2019.