St. Joseph Mercy Health System wants to build larger outpatient operating rooms at its facility in Superior Township, Crain’s Detroit Business reported.

In a letter of intent submitted last month to the Michigan Department of Community Health, the hospital indicated it wants to build a $29.3 million, two-story, 42,910-square-foot addition, the publication reported.

In 2010, the hospital completed a major expansion with the opening of a new $115 million seven-story patient tower.

Hospital officials have said the current outpatient surgery facilities are too small for technology improvements that would improve the quality of outpatient care.

The hospital has said it wants to have eight operating rooms, each about 500 to 600 square feet, Tocco said.

The second floor will have two “hybrid” operating rooms, which will be about 900 to 1,000 square feet each. Only one of the rooms will be fully completed during the initial construction project, Tocco said.

The hybrid operating rooms incorporate interventional radiology with traditional operating room functions, officials said.

• Read the article in Crain’s Detroit Business.