The Treasury of Notre-Dame de Paris has not been moved much over the centuries. It has always been kept in a building located perpendicular to the cathedral near the South deambulatory chapels. The former constructions also housed sacristy rooms used by priests in charge of the church, as is still the case today.
In the 18th century, these annex constructions were in near ruins, and Soufflot (1714-1781) was asked to draw up blueprints for a new sacristy. The first stone was laid on Thursday 12 August 1755. This large sacristy was built in two years and aimed to combine the Greek and Gothic styles. It clashed with the rest of the cathedral. The sacristy was accessible from a two-rail spherical back staircase whose sculpted cabinets housed shrines and relics; ornaments were placed on an upper level. This building did not stand the test of time, not even surviving a century. The riots of July 1830 and February 1831 ravaged the archbishopric and the sacristy so badly that it would have been impossible to restore them.
Only the sacristy had to be rebuilt between 1845 and 1850 by Lassus and Viollet-le-Duc around a small square cloister which provided access to the cathedral by two arms. The part closest to the transept was for the faith and the other part housed the Treasury. The cloister stained glass windows, by Gérente, depict the life of Saint Genevieve. The Treasury room’s stained glass windows, which represent the bishops and archbishops of Paris, were made by Maréchal de Metz. The relic cabinets and cope holders were made by the joiner Mignon based on Viollet-le-Duc’s designs.