Casa Alesan is one of the most distinctive properties on Sant Joan Boulevard in Barcelona, on a par with Josep Puig i Cadafalch's Palau Macaya also located on the same street.

In 1902, Dolors Alesan commissioned it to architect Enric Fatjó i Torras, who designed the Art Nouveau architecture: stuccoes, stone sculptures, metalwork and stained glass stand out on the facade, while inside, hall and staircase are the protagonists, valorized by a skylight on the roof. 

In the flats inside, today one can admire tiled floors and plastered ceilings, original features that studio BACH was able to preserve. Restored and extended by increasing the number of flats, the property offers a skilful dialogue between old and new. The architects have in fact catalogued the various historical elements of the property and maintained the original perimeters by working with volumes that do not touch the ceilings.

The extension, on the other hand, is defined by a different nature in relation to the main structure, stressed by the distinction of new and old volumes: this addition is distinguished by a facade in vertical and circular ceramic slats, selected for giving lightness to the building and establishing a harmonious chromatic relationship with the palace and the adjacent historical architecture.