Apple on Thursday previewed its Carnegie Library store in Washington, D.C., set to open on Saturday at 10 a.m., saying it will help the Library once again serve a public good despite much of it being turned into a private store.

The store represents Apple's "most extensive historic restoration project to date," the company said. The building was originally Washington's Central Public Library, funded and opened by Andrew Carnegie in 1903. Apple worked with conservation experts on preserving facades and details, and restoring interior spaces to their original dimensions. Apple's usual architectural firm, Foster + Partners, operated in conjunction with chief design officer Jony Ive.

"I love the synergy between old and new, the juxtaposition of the historic fabric and contemporary design," Ive said in a prepared statement.

The exterior has a revamped K Street plaza, as well as a new staircase on Mount Vernon Place. Lighting comes partly from a restored skylight.

The building hasn't been completely handed over to Apple. The iPhone maker will share space with the D.C. History Center, which includes the Kiplinger Research Library, three galleries, and a museum store. A new grand staircase connects to the Center on the second floor.

As previously announced the outlet will be holding a "StoryMakers Festival" between May 18 and June 29, consisting of Today at Apple sessions from 40 artists.