TEUTOPOLIS, ILL. — An expansion and updating of company offices is under way at Siemer Milling Co. in a project that will bring the company’s administrative staff under a single roof.

Richard C. Siemer, president of Siemer Milling, said the project will include the construction of a new structure that will be attached to the company’s current headquarters. The older space, which dates back to the 1880s, will be remodeled once the new building is finished. Groundbreaking ceremonies were held July 25, and the new building is expected to be completed in May 2014. The rest of the project will be finished by late July.

“When the project is completed, all administrative functions will be together in one building for the first time in 50 years,” Mr. Siemer said.

The idea of bringing everyone at Siemer together also informed design decisions for the new offices, Mr. Siemer said.

“It will be a very open concept,” he said. “No one will have four walls and a door, including me. We’ll be close enough to one another to learn what’s going on by overhearing. It will give us the ability to interact, to maintain a sense of collegiality.”

Overall, the company will be doubling its administrative space to about 13,000 square feet. The addition will give the company space for additional growth.

When the building is completed, staff officing at a building down the street from the headquarters will move into the new space. Once this move is made, Mr. Siemer said laboratory and research facilities, already operating in that building, will be expanded.