Administrators of Maine Medical Center are proposing a massive expansion project that stands to become the largest ever undertaken by the hospital.

monkeybusinessimages/Thinkstock

If approved, the $512 million expansion would add 300,000 square feet to the hospital's main campus in Portland — increasing its footprint by approximately 25 percent.

While the project calls for the addition of 20 operating rooms, the total number of beds at the hospital would not change.

Instead, more of the hospital's 637 beds would be relocated to private, single-patient rooms. Currently the hospital has 303 double-occupancy rooms, which Maine Med officials say is no longer the standard of care.

The project is expected to be completed in 2022 if Maine Med receives all of the necessary permits. Approval is needed from both state and local governments.