This vertical extension project was set in one of the most spectacular locations in Barcelona, in the middle of Passeig de Gràcia, overlooking Gaudí’s Casa Milà. The project developed two symmetrical two-story housing units, favoring the exploitation of exterior spaces, with various terraces oriented according to sunlight and views. The structural system, made of pre-assembled steel modules, enabled rapid execution and an acceptable increase in additional loads to the existing structure.