On top of strong residential growth, downtown St. Paul and surrounding areas have experienced a slight uptick in occupancy of high-end, or “Class A,” office space, though the total amount of office space remains unchanged at 16 million square feet.

The Greater St. Paul Building Owners and Managers Association, or BOMA, on Friday released its annual St. Paul Market Report, which found that 90 percent of downtown St. Paul office space is occupied. The vacancy rate for Class A office space was 15.11 percent in 2016 and has since dropped to 14.49 percent.

Overall, Class A office space — known for having the highest amenities — makes up 27 percent of the downtown market. “The square footage didn’t increase, but the vacancy changed,” said BOMA President Joe Spartz. “There’s more occupancy in Class A.”

Composing 66 percent of the market, Class B, or second-tier, office space represents the majority of what’s available in and around downtown St. Paul. Overall, Class B occupancy rates dropped from 82 to 76 percent, mostly due to the departure last year of Cray Inc. from Cray Plaza to Bloomington and Ecolab’s corporate headquarters move down the street into the former Travelers Tower. At 7 percent of the market, Class C office space has shrunken over the past decade as developers convert those structures to residential uses.

Formerly owner-occupied, the old Ecolab headquarters on Wabasha Street is being refurbished into 129,000 square feet of Class B office space under the title Osborne 370, and is about 60 percent occupied. The Degree of Honor and Capitol Professional Office Buildings have been converted to other uses and dropped out of the office report. “Those are part of the continuing conversion process that we’ve been seeing in downtown St. Paul for a number of years, and it’s going to continue on for a number of years,” Spartz said. “Next year, we’ll probably see one or two more office buildings drop out of the report.”

The report looks at downtown and the area south of downtown to Plato Boulevard and north to University Avenue.

The report cites a study from Maxfield Research that found the total number of people living in downtown St. Paul to be 4,862 in 2010 and 8,943 as of August 2017, an 84 percent increase. The vacancy rate for downtown rentals is 4 percent, while the vacancy rate for owner-occupied units downtown is less than one-third of one percentage point. BOMA will conduct its retail study in 2018.