This project consists of a viability study of the reconversion of use of two buildings located on the old part of Sitges town in order to enlarge the recently inaugurated museum of contemporary art. The first step to execute the project is to make a study of every building whose use is to be reconverted. This study will provide all the necessary data to subsequently make the executive project of enlargement. At this point, we will analyse different aspects, such as constructive characteristics, conservation status, urban development situation and protection patterns of these buildings. Starting from a basic project as point of reference for the enlargement, the project will analyse, in execution order, the interventions that are to be applied. As every intervention is studied in depth, a solution to different situations that rise during the project is provided. This way, we’ll deal with issues such as inner demolition of buildings protected by special protection plans of cultural heritage, which oblige to maintain facades and eaves, both during the demolition process and the execution of the new structure. These masonry facades will play an important role in the structure of the new building. Throughout the project, we will focus on rehabilitation issues, such as the reinforcement of a ceiling made of wood beams to make it suitable for the public use, protection treatments in ceiling’s wood beams or treatments against moisture in masonry walls to be conserved. Once the structure of building #1 is done, we will proceed with the execution of openings in party walls, which will connect the three buildings. This will enable the communication between the current museum and buildings to be rehabilitated. The last stage of the project will be focused on the installations analysis and the finishing of the museum complex. Special attention will be given to those installations that have more importance in buildings of this kind, as for example illumination and acclimatisation of the exhibition halls. The execution project will be accompanied by the Study of Security and Health, which will be applicable to the partial work of demolition and new works, as well as to the work of rehabilitation and finishing of the complex.