Chocolate manufacturer Antoni Amatller i Costa commissioned Catalan architect Josep Puig i Cadafalch to transform an existing building into a residence for his family. From 1898 to 1900, Puig i Cadafalch worked to make what was essentially a block of flats appear to be a single urban Gothic palace.
Under the architect’s supervision, the building's facade was demolished and rebuilt with a variety of colors and decorative sculptural iconography. There are allusions to the family name such as flowering almond tree branches twisted into capital A’s, traditional references to Sant Jordi and the dragon, and around the three balcony doors one of Puig i Cadafalch’s hired artists painted an allegorical portrait of Antoni Amatller using symbols to depict the three fields that best defined him: industry, the arts (especially photography) and his collection of archaeological glass. Puig i Cadafalch also altered the distribution of the main floor, refurbished the staircase, added an electric lift to the building and installed a rotating platform for the owner’s automobile.
The renovation of Casa Amatller defied the building criteria established in Ildefons Cerdà’s plan city plan. Puig i Cadafalch went against the main classicist rules of symmetry and regularity; the singular stair-like top that crowns the building and integrates the photographic study built on the roof surpassed the 22-meter height limit of city structures; and he added the concept of color as a prominent feature in a sea of grayscale urban surroundings. With one house, he redefined a district rooted in uniformity and brought Modernisme to the Eixample.