An artist’s rendering shows one of the entrances to the underground expansion of the Folger Shakespeare Library. (Folger Shakespeare Library)

Home to the world’s largest Shakespeare collection, the Folger Shakespeare Library is planning an underground expansion to draw more visitors to its renowned holdings and spark interest in the playwright’s work.

“This gift to the American people will really be unwrapped,” Folger director Michael Witmore said of the construction, which is set to begin next year and completed by 2022.

The library will announce a $50 million capital campaign on Monday to support the addition to the institution, which was founded in 1932 by philanthropists Henry and Emily Folger. The library has already raised $25 million toward its goal for the two-year project, which requires approval from two federal agencies.

The Folger plan is similar to an initiative proposed at the Library of Congress, its neighbor on Capitol Hill, to make its vast collection more accessible to the public.

Designed by Kieran Timberlake architects, the project would add 12,000 square feet under the library’s north lawn. Entrances on both ends of the marble building would be surrounded by gardens designed by OLIN.

“The idea is to use the landscape as a guide, to come down the garden path,” Witmore said.

Inside the new space, the North Hall would feature a vault for the library’s 82 Shakespeare first folios, the first collections of Shakespeare’s plays published in 1623. In addition, four immersive galleries would pose questions — such as “How does it feel to be an outsider?” and “Do you deserve what you take by force?” — to introduce visitors to Shakespearean themes. Live-action video and projection of play excerpts would also be used to help visitors learn about the plays, Witmore said.

Another new exhibition hall would display the library’s treasures as well as provide room for changing exhibitions.

These new spaces mean that the Folger’s Great Hall, now used for exhibitions, would return to its original use as a gathering space for visitors, including audiences attending performances at Folger Theatre.

The expansion plan solves some of the historic building’s accessibility problems without changing its stately exterior. The library’s reading rooms and collection storage would still serve scholars and curators, Witmore said.

The library opens an exhibition Saturday exploring the history of the Paul Philippe Cret-designed building. “A Monument to Shakespeare: The Architecture of the Folger Shakespeare Library” will run until January, when the building is set to close for the expansion. Theater performances would continue at Folger through March 2020 and then be staged off-site until the reopening.