The Brooklyn, N.Y.-based owners of the Spring Mill Corporate Center plan to spend more than $10 million to partially demolish a former industrial building at the Conshohocken complex for conversion into 42,000 square feet of new offices, with picnic space and additional parking.

Kalmon Dolgin Affiliates Inc. said in a release that its renovation plan for what is now a 635,000-square-foot, four-building office park at 1100 E. Hector St. also includes 25,000 square feet of amenities, such a new lounge and exercise room, in the campus's main building.

The 36-acre campus is the former site of Lee Tire Co.