At the same time, the iron and steel industry went through a boom and iron media started to be used in building. The first building in which this technique was used, barring the market and stations, was the Montaner i Simó publishing house in Barcelona's calle Aragó.
Moreover, cast iron was also being used in the building of fountains, lampposts, benches and other elements.One of the main prime movers in furthering the use of cast iron was Valentí Esperó. He was a city councillor who introduced casting in 1832, and was the co-founder of Maquinista Terrestre i Marítima, a key company in the building of metal structures.
This is how metal structure buildings gradually emerged in Barcelona, illustrating the possibilities of the new material. Iron was used in the building of facilities, industries, monuments, bridges and urban projects.