Paso a Paso is a response to one of the building solutions in our country: the self- building. The proposal synthesize the client’s requirements –one and two story house prototypes–. Current Casita Linda ́s prototypes, although esthetic, efficient and decent, do not encourage the possibility of adaptation and additional growth by their owners, they just respond to a necessity that is limited in time without allowing future changes. Paso a Paso is a one and a half story house that allows a progressive and planned three stages self-building until it transforms into a two and a half story house within the same ground level borders. The house begins as a free and flexible space, in which with minimum interventions it is able to split into two bedrooms, social area and a tapanco –surface placed to divide vertically the space up to 100% of the ground level–. The second stage considers the construction of half the second level walls (50% of these walls remain from stage one) in order to have a two story house. The third stage consists of the construction of the walls to place a tapanco area. In order to reach this building growth, the rooftop has been solved with a light, lasting and insulating roof (wood frame, thermo-acoustic insulation and metal sheet roofing) which hinges upon one of its large sides to be adapted during the three stages without being dismantled. The progressive growing characteristic of the proposal will create a sense of belonging and customization, and a sustainable housing model that can be adapted according to the needs, possibilities and desire of future users through time.