The Casa Calvet was built by the children of textile manufacturer Pere Màrtir Calvet, who set up the business founded by their father in the basement and ground floor, while the first floor was used as the proprietors` home and the upper floors were rented out. This block of dwellings constitutes one of Gaudí's least bold works, with a symmetrical façade that recalls a modest early Modernisme construction. Only careful attention to the details reveals the architect’s brilliant hand. Of particular interest is the entrance, flanked by columns in the shape of bobbins and an original wrought iron door knocker: a cross that comes down on a bug, symbol of the faith that destroys sin. Over the main door is the colourful first-floor gallery, with sculptural representations of flowers and mushrooms, a shield of Catalonia and references to hospitality (a cypress), peace (an olive branch) and abundance (two horns of plenty). A final point of interest is the façade's cornice, with three busts of holy martyrs and two balconies of cast iron at the front, anticipating those at the Casa Batlló.
The interior of the building also has Baroque decoration, particularly in the entrance hall, but Gaudí’s main concern was the functional layout of the space. So for example, he placed the inner courtyard near the stairs to give it a better lookout. This was one of the things that the jury of the first annual competition for artistic buildings in Barcelona took into account when awarding their prize to the Casa Calvet in 1900.