A four-story office building in LoDo has changed hands.

Denver-based Urban Villages and related entities paid $10.04 million on Thursday for 1614 15th St., according to county records.

The structure, which dates to 1890 and is approximately 24,000 square feet, is commonly known as the Rock Island Building. The name stems not from the railroad that once served the region but rather after the Rock Island nightclub, which operated in the building’s lower levels for 20 years, closing in 2006.

The property was sold by Denver-based St. Charles Town Co., which purchased it for $2.85 million in December 2006, according to records. The previous owner had operated the nightclub and was looking to sell. St. Charles already owned the structure next door at 1600 15th St., which it still holds today.

St. Charles founder and President Charlie Woolley said that, after purchasing the structure, his firm undertook a “top to bottom and structural renovation,” which included replacing all the windows, adding structural reinforcements and installing new elevators.

Woolley said his budget for buying and renovating the building was about $7.5 million.

“Back then, it was a lot,” he said. “Today’s dollars? Nah. It’s so expensive to do renovation work today.”

The building, which in addition to the upper four floors also has office space in a basement, is fully leased. Tenants include L&E Research, JourneyApps and public relations firm Turner.

Darrin Revious of Pinnacle Real Estate Advisors represented the buyer in this week’s transaction.

Urban Villages spent $7.4 million this month on three office buildings in the Golden Triangle. The firm also is partnering with Larimer Square owner Jeff Hermanson on his plans to redevelop no-historic portions of the prominent downtown block.