Partly inspired by the Barrière Saint-Martin (Rotonde de la Villette) by Claude Nicolas Ledoux, Asplund abandoned earlier ideas for a dome in favour of a rotunda whose tall cylinder gives the exterior some monumentality.

Officially opened on 31 March 1928 in the presence of Prince Eugen, due to financial constraints the library was still missing its west wing which was only added in 1932 to complete the approximately square base around the rotunda of the main reading room.

[1] Charles Holden's design of Arnos Grove tube station in North London is said to be based on the Stockholm Public Library.

Her project includes a high-rise glass building, spatially removed from Asplund's main library but connected to it by a low, podium-like structure with a semi-circular courtyard into which the slope of the Observatorielunden seems to flow.

This was due to a change in city government with different priorities[5] as well as a local campaign turned international about what critics saw as an unacceptable impact on the original, Asplund approved complex.