This project was developed in Gandía, a town with a population of 75,000 to the south of Valencia. The aim was to develop a hybrid project that would function essentially as a student residence while meeting the requirements of social housing, with the corresponding standards and characteristics. The proposed program includes 102 apartments for young people, 40 apartments for senior citizens, and a civic and social centre for the town council. The most interesting question from a programmatic point of view is the provision of shared spaces in the apartments for young people, which is in effect a new version from the traditional residence for young people. In Spain the national Housing Plan clearly establishes that apartments can be built with an area of between 30 and 45 m2, with up to 20% of shared space, but does not specify where or how this should be located. The fact is that the idea of sharing spaces is fully compatible with the goals of social and environmental sustainability, grounded as it is on the principle of ‘doing more with less’: that is, offering people more resources through the mechanism of sharing. Recent analyses have identified a minimum of thirteen basic functions related to the fact of dwelling. Some of these are clearly private (sleeping, bathing, etc), while others can have a semi-public or shared nature: eating, relaxing, digital working, washing clothes, etc.These resources can be shared within a single dwelling, between two dwellings, between individuals on the same floor or two adjoining floors, on the scale of a whole building or between different buildings in the same neighborhood. The key, then, is to choose the scale at which we want to share resources so as to create a particular model of habitability or another. If we construct 102 apartments of 45 m2 each, which may share 20% of their floor area, we can have up to 918 m2 of shared space. This could be in the form of 51 shared spaces of 18 m2 (each apartment in a pair contributing 9 m2), or a single space of 918 m2. Our proposal puts forward an interesting and innovative model with which to define three scales of habitability:A first, individual scale of 36 m2, comprising the kitchen, bathroom and rest area in a loft-style apartment. A second, intermediate scale of 108, 72, 36, 24 and 12 m2, shared by 18, 12, 6, 4 or 2 people, on every second floor. This comprises a spacious living area and contact and work areas. A third and larger scale of 306 m2, shared by all 102 people and located on the ground floor, which will include a lounge, a laundry, Internet access and a library.