Developers plan to expand the event space at the Depot by enclosing the remaining eastern portion of its historic Minneapolis train shed.

The Depot, located on the corner of Washington and 3rd avenues S. in downtown, will gain an additional 24,000 square feet of space that now serves as a covered parking area. The former Milwaukee Road Depot shed is already home to the Depot Pavilion that is used as event space as well as an indoor ice rink.

The expansion is the second phase of the depot’s conversion by Minneapolis-based CSM Corp., which entered into a development contract with the city in 1999 and agreed to fully convert the train shed over a span of 20 years.

CSM declined to comment on its new project, but it detailed its intentions in a Nov. 22 letter to the Downtown Minneapolis Neighborhood Association.

“CSM is extremely excited to add much needed banquet space to our thriving Milwaukee Road Depot development,” John Ferrier, CSM’s vice president of architecture, said in the letter.

Currently, the Depot has more than 66,000 square feet of event space at its complex, which includes the Renaissance Minneapolis Hotel and a Residence Inn. Earlier this year, CSM added 110 rooms to the complex by building a sixth floor and removing a water park in the hotel.

The train shed and the adjacent depot building were built in the late 1800s and were designated historic landmarks in 1979, eight years after rail service was discontinued. Ferrier insisted that the historic elements of the truss-roofed shed be preserved. The remainder of the train shed will be enclosed with glass, as was done with the pavilion.

CSM has submitted its expansion plans to the city and the Historic Preservation Commission, Ferrier said in the November letter. The project is on the agenda of the Jan. 3 meeting of the neighborhood association’s land use committee.