The function of the underground ice storage, Glacières Royales, was to efficiently conserve ice during all seasons. It consists of a large vaulted structure in masonry from floor to walls and ceiling, covering 460 m². This remarkable ice storage is no longer in use today but is one of the last monumental witnesses of the European industry of ice and is therefore listed since 1993. A real estate project influencing the immediate surroundings of this ice storage motivated a thorough evaluation of its condition and stability. The actual structural behaviour of the underground ice storage, Glacières Royales, was studied. 2D and 3D numerical models based on linear elastic finite elements were used for the masonry. The soil-structure interaction was modelled by linear and non linear models using the Plaxis software. Analyses are presented both on the level of stability of the Glacières Royales in its present and future conditions imposed by the real estate project.