On March 4, the Martin Luther King Memorial Library in Washington D.C.—an historic landmark designed by Mies van der Rohe that opened in 1972 and serves as the city’s central library—will close for a three-year, $208-million modernization. Dutch firm Mecanoo architecten, working with D.C.-based Martinez+Johnson Architecture, will adapt van der Rohe’s building into a “library of the future.” Included in the plan are improved reading rooms and employee experiences, expanded kids areas, and a new green roof that will serve as a “pocket park.”

The project is an extensive overhaul of one of the most historically important civic buildings in Washington. And a 62-minute film made by Mecanoo, A Legacy of Mies and King, premiering at the library today, documents its evolution and the firm’s sensitivity to the library’s architectural and cultural significance.