New York developer completes $14.5M purchase of Commerce Building in downtown Worcester The nine-story, 380,000-square-foot building is known as the downtown’s first office "skyscraper." SilverBrick Group LLC purchased the 340 Main St. building from Commerce Associates, which also owns properties at 332 Main St. (Central Building), 244 Main St. (Irish Times building), 18 Chestnut St. (former Unum building) and several surface parking lots. The transaction was recorded at the Registry of Deeds last month. SilverBrick Group is looking to invest $54.45 million to create the market-rate housing over two phases, with commercial uses on the first floor. The apartments will be 80 studios, 183 one-bedroom units, 39 two-bedroom units and 10 three-bedroom units.