Developers will break ground Tuesday afternoon on an expansion of the Aspen Brook Centre in Cool Springs that will become the home of FirstBank’s most prominent Williamson County office.

FirstBank will move its branch from the Dover Centre on Seaboard Lane, where it signed a lease extension two years ago. Joining the lender at the second phase of Aspen Brook is Premier Radiology, which is part of the Saint Thomas Imaging Network and a tenant of Aspen Brook’s original building. Franklin-based architectural and development firm The Innovations Group is spearheading the project.

At about 4,000 square feet, FirstBank’s new Aspen Brook location will be more than twice the size of its Dover Centre office, allowing the bank to allocate space for its FirstBank Investment Partners and FirstBank Mortgage Partners divisions.

“The new Aspen Brook Centre II development is an ideal location for us,” said Brit Boatright, FirstBank’s metropolitan bank president. “This move will give us increased visibility in the community, a drive-thru window and more space to better serve our customers.”

FirstBank runs 12 offices in Middle Tennessee and ranks 15th in deposit market share. The bank late last year recruited Gordon Inman, the former chairman of Franklin National Bank and Fifth Third’s regional operations, to be the face of its Middle Tennessee franchise.