The redesign will keep in place the building shape created by modernist architect Ludwig Mies van der Rohe. (Callan Swenson)

The District’s central library will close March 4 for a three-year renovation under a timeline released Thursday.

During the closure, rare collections housed at the Martin Luther King Jr. Memorial Library will be dispersed across the city. At neighborhood branches, hours and computer resources will expand to cover expected increased demand, said D.C. Public Library Executive Director Richard Reyes-Gavilan.

The long-planned makeover of the building at Ninth and G streets NW is expected to cost the city $208 million.

The final design took shape over the past two years, after a proposal to build private offices atop the library to offset renovation costs fell through. A study of the proposal found it would not generate enough revenue and would complicate public use of the building.

The redesign will keep in place the building shape created by modernist architect Ludwig Mies van der Rohe. But the redesign of the 1970s-era building calls for a large new auditorium and rooftop terrace, as well as open floors, more natural lighting and a new entranceway and sculpted staircase.

The library’s historical Washingtoniana Collection will be split into three sections, available at the Washington Historical Society, the Georgetown Library’s Peabody Room and the Library of Congress, according to Reyes-Gavilan.

The library system will also disperse 50 laptop computers to neighborhood branches and keep branches open on Thursday mornings, when they are now closed, to serve library patrons who might otherwise have ventured downtown.

In addition, the library system will open a “Library Express” location at 1990 K St. NW.