The abbey−choir building had been used for secular purposes since the 16th century Protestant Reformation, and was transformed by the installation of shelves into a warehouse building. For several centuries it was used as a granary. Since 1914 the choir building has been administrated by the "Zentralbibliothek" (Zürich central library), the main library of both the canton, city and the University of Zürich. From 1919 to 1982 it also housed the "Staatsarchiv Zürich" (state archives of the Canton of Zürich), before they moved to the Irchelpark campus of the University of Zürich. The Zentralbibliothek Zürich (literally Zürich Central Library) in the Predigern's choir passed over from the church to the University of Zürich to the "agreed plans for library purposes" according to the "treaty between the Canton of Zürich and the City of Zürich regarding the establishment of a Central Library, from 10 December 1910". On 28 June 1914, the citizens of Zürich agreed to the establishment of the "Zentralbibliothek", that was according to the plans by Hermann Fietz was built between 1914 and 1917, situated at the former site of the old monastery buildings. Because the wooden shelves were seen as a security risk, they were replaced in 1918/19 by a concrete construction, though already at that time there were objections against this plan. The book magazine built on the place of the old cloister, now directly connected to the Gothic choir and making the 1871 exemption for the time being reversed. From 1917 to 1919, the final transformation of the choir to library purposes took place, and in 1919 the choir was leased to the Canton of Zürich, and so the cantonal library was outsourced, however in 1919 moved back and again moved, to make room for the as of today "Staatsarchiv des Kantons Zürich". Therefore, since 1982 the premise is used for the library, in particular for its Musikabteilung, meaning the music department of the University of Zürich. By the cantonal "Hochbauamt" (literally: building construction departement) the construction works were performed in the Prediger choir in March 1941, mainly in the roof of the choir, where in setting up a makeshift lighting, a medieval grave stone was discovered in the attic, which was walled up there.