The historic downtown campus of First Baptist Church Dallas will undergo a multimillion-dollar overhaul. New construction includes a 3,000-seat sanctuary, five-story education building, seven-level parking garage, fountain plaza and sky bridge.

The church’s congregation pledged to fund most of the $123 million project, which is the largest-ever expansion by a Protestant church, according to church officials and local media.

Manhattan Construction Co. of Dallas was selected as construction manager and, in turn, selected Prism Electric to provide electrical construction services. All told, there will be 1.5 million square feet of buildings on the expanded campus. The new sanctuary will house nearly two miles of pews. The original sanctuary, built in 1890, will be preserved.

Plans call for new construction to be LEED-certified. First Baptist Dallas has a Construction Web Camera on its website,