The Martin Luther King Jr. Memorial Library. (James M. Thresher/The Washington Post)

THE QUESTION of what to do with the Martin Luther King Jr. Memorial Library has vexed the District for a decade. When he was mayor, Anthony A. Williams (D) thought the historically protected building unusable as a modern library and wanted to build a new facility elsewhere. In his turn, Adrian M. Fenty (D) thought Bloomingdale’s might locate there, while Vincent C. Gray (D) hoped to renovate the building through a public-private partnership that would share the premises with a paying tenant. Now comes an exciting plan developed by library officials that we hope will have better success than the unrealized ideas of the past.

The plan calls for modernizing the aging steel-and-glass building designed by Ludwig Mies van der Rohe and adding an extra floor and roof garden to create what officials describe as a hub for educational, cultural and civic expression for the entire city. The distinctive work of one of the most important architects of the 20th century would be preserved but opened up to space and light — made more useful and, in the words of the library’s executive director, Richard Reyes-Gavilan, “more delightful.” The upgrade is estimated to cost between $200 million and $225 million.

The plans were developed after library officials received feedback from more than 3,000 residents about what they want in a library and studied successful central libraries around the world. Traditional features such as a reading room and book stacks would remain. But there also would be hands-on learning areas, a digital commons, performance rooms and collaboration spaces, enabling a “dizzying array of services,” Mr. Reyes-Gavilan says. Daily users, he projects, would rise from 2,000 to 5,000. The facility would be a resource for city agencies and like-missioned nonprofits: The Department of Employment Services would teach people to apply for jobs there, DC Health Link would walk residents through how to apply for health benefits. Young children would be made to feel welcome.

Obstacles to the plan still exist, but library officials seem to be well on their way, having hired architects and worked closely with the federal planning agency that will have to sign off on the design. The District government has committed $208 million in its multi-year capital budget for the work. Library officials hope to convince Mayor Muriel E. Bowser (D) and the D.C. Council to accelerate the pace of financing so that construction could begin in late 2016, with the modernized library opening in late 2019. That would likely mean delay of another capital project, but we hope officials find a way to speed completion of what has long been an unfulfilled need: a central library worthy of this capital city.