The purpose of this project is the promotion of private houses and commercial spaces in the building located in Ataülf street N.7 in Barcelona. This building was built in 1850, placed between buildings and ground floor.It has a mezzanine and four floors. At the ground floor the spaces are designed for commercial and housing uses. The project site is located in the Gothic Quarter characterized by a consolidated urban grid. To us, who are building today, we would like someone tomorrow who will treat our work with the same shrewdness. All apartments will have natural ventilation, providing cross ventilation where is possible; It is also guaranteed the direct natural enlightment of the room between 10 and 12 hours in the winter solstice. The treatment of the housing ensures maximum comfort and maintains the character of the houses of Barcelona.