Abstract is exactly "One of the most important decisions to be made in the design process of a building, is the choice of the materials and the construction technique to be used, that is, the selection of the Construction System. When making these decisions, the criteria that historically prevailed were of economic and/or cultural nature. However, since the emergence of the concept of Sustainable Development and its application in the different construction areas, the decision criteria have been expanded to include environmental and social variables. Considering Sustainability as the simultaneous analysis of environmental, social and economic aspects, this thesis will encompass the two first, understanding that currently the economic variable is the main decision making parameter. In this thesis, a group of Sustainability Indicators is selected and defined, according to the argentinian reality, which allows to evaluate exterior walls built with different Construction Systems. The unit of comparison between them is 1 m2 of wall. In this way, it is intended to generate tools that allow those who must choose in the design phase of a building, the Construction System to be used, to do it with Sustainability criteria. For such objectives, it is used the scientific methodology known as "Life Cycle Assessment”, through which there were studied the environmental impacts generated during the Life Cycle of a building and, on the other hand, the social impacts. For the latter, it was taken into account the inclusion of the main stakeholders involved. This analysis resulted in the proposal of Environmental Indicators and Social Indicators that allow to evaluate the degree of Sustainability of the Construction System that needs to be studied. The set of these indicators are the so called Sustainability Indicators."