WASHINGTON — Arena Stage has raised more than $100 million toward a capital fund-raising campaign for a dramatic expansion of the org’s facility on the D.C. waterfront.

Adding to the theater’s existing two stages, the $120 million complex will sport a 200-seat black box theater for new works, as well as spaces for rehearsals, classrooms and set design; onsite apartments for artists; a cafe; and administrative office. All will be housed under a single sweeping roof designed by Vancouver’s Bing Thom Architects.

New facility will be named Arena Stage at the Mead Center for American Theater in honor of local arts philanthropists Gilbert and Jaylee Mead, who have contributed $35 million toward the project. Arena said the money reps the largest single gift ever made to an American regional theater.

The support of the Meads included a pivotal gift in a difficult fund-raising climate: a $20 million one-to-one match extended last year. Arena met conditions requiring that only gifts of $500,000-plus would be matched.

The largesse was praised by a.d. Molly Smith, who pledged a new era of creativity for Arena and an important home for American playwrights during Wednesday’s press conference. Continued emphasis on American works will include an Arthur Miller festival next season, Smith said.

The new Arena facility will launch a large-scale revitalization of the southwest D.C. waterfront planned by local government. Arena said it will begin the bidding process for construction.

In addition, Arena has launched a partnership with the Georgetown U. theater program to collaborate on play-development workshops and other projects.