Massachusetts General Hospital (MGH) is the third oldest hospital in the United States. It has been ranked the fourth best hospital in the United States, and it holds the largest hospital-based research program in the world.

The institution is so prestigious that federal authorities announced earlier this week that it would be the base of a new study on the long term effects of the coronavirus.

Now, Turner Construction Company and Walsh Brothers Inc. will be working together on expanding this behemoth of an institution, with NBBJ handling the design.

As local newspaper the Beacon Hill Times reports, the more than one million square-foot expansion will feature two 12-story towers with a connection between them. The expanded campus will also be getting an underground parking structure featuring six stories. The new building will also use 95 percent renewable energy.

The 12-story towers will be equipped with 482 new hospital beds, new imaging and lab spaces and exam rooms, while the parking structure will feature 971 new parking spaces. A bike storage space will be able to accommodate 1,043 bicycles. The project will also feature expanded sidewalks among other improvements.

Subway system extensions are also being discussed

Construction on the project will begin in the summer of 2022 and is expected to take seven years.

Demolition will have to be completed on aging buildings in the area; historic structures that have been around for more than a century.

“MGH has done a really exceptional job to compensate the West End and Beacon Hill communities for the loss of these structures,” Sebastian Belfanti, the director of the museum in the area said. “I’m really excited to work with MGH to get the historical displays up to educate visitors to the new building.”