 The frames are then Valognes stone (limestone), pink granite of Fermanville, or brick, and the underpinnings Armorican sandstone of the Roule and the Fauconniere.The expansion of the city from the 18th century contributed to the diversity of materials.The use of Caen stone and industrial brick was necessary under the Second Empire, while vernacular architecture disappeared gradually in these years in favour of a more homogeneous and Parisian style.