Labrouste included both modern and classical elements in his Bibliothèque Nationale. Many elements he included have appeared in other architectural periods liked the ribbed vaulting, and the ionic columns and capitals. Some more modern elements were the inclusion of cast iron in the arcuated windows and columns instead of stone. The cast iron was able to withstand a much larger load than stone could, so the columns are able to be smaller. Also, he used plaster to further increase the strength of the building.