AHN Allegheny General’s 90-year-old, 22-story South Tower is slated to begin a 4-year, $36 million renovation in June.

The project checklist at the hospital system’s flagship academic medical center on the North Shore includes an overhaul of the facade’s masonry and ornamental terra cotta, replacement of more than 800 windows and the repair and replacement of 60,000 square feet of roof, according to a press release from AHN.

The project’s focus is “extending the life” of the 467,000-square-foot building and “maintaining its original architectural beauty.”

“As the building ages, there are several things requiring attention,” said hospital spokesperson Candance Herrington of the project that will be funded entirely by AHN.

Hospital officials say they will utilize “traditional craftsmanship” and “modern techniques” through Mascaro Construction Company to preserve the character and striking top-section cathedral windows of the 1936-built historic structure. It was one of the first high-rise hospitals in the U.S. (The “cathedral” portion itself is a modern day interpretation of Ancient Greece’s Mausoleum at Halicarnassus).

Hospital officials said patient care and hospital operations “will not be impacted at any time during work on the tower.”

Herrington noted that there will be no layout changes as part of the work that is completely external.

“This project is critical to ensuring the hospital’s South Tower remains a cornerstone of our clinical campus and home to many offices and clinics that support our exceptional caregivers and help us deliver remarkable health experiences to those who receive our services,” said AGH president Dr. Imran Qadeer in the release.

The 508-bed Level 1 trauma center — which in recent years has served as a backdrop and inspiration for HBO Max medical drama “ThePitt” and its fictional Pittsburgh Trauma Medical Center — employs 5,000 in areas including cancer care, cardiovascular medicine and surgery, orthopedic surgery, organ transplantation, ophthalmology, plastic surgery, radiology and more.

“ ‘The Pitt’ didn’t play any role in the timing or specifics of the project,” Herrington said. “However, we’ve alerted production that the South Tower will be covered in scaffolding for the next few years.”

AHN, which owns 14 hospitals in the greater Pittsburgh area, last May began preparing for a $43 million expansion to Allegheny General’s emergency department and also recently announced the addition of a new $13 million helicopter to its LifeFlight fleet.