This research stems from the need to know how to build a sustainable public space, without compromising the resources of future generations and ensuring existing resources.The research is a reflection on criteria to build an efficient Public Space : a harvester, manager and optimizer of the resources for the city with the minimum resources. Thus, public space becomes not only a social-leisure place but also a vital organ for the city as if it were a living entity; a living entity with vital functions such as: recovering the water cycle, managing it according to our needs (drainage, harvesting, transportation, etc. ..), harvesting and managing energy resources reducing its consumption, preserving green ,optimizing life cycle of the materials used in its construction or reducing the climate impact in the atmosphere as much as possible.The article is a summarize of a major research. It's just structured under an environmental responsibility point of view. It's divided in 5 areas or resources: water, green, subject, energy and atmosphere. Each area has two different parts. The first one analyzes the general concepts and quantifications which are always a study case (by experts or Phd researchers) or a real monitored case. Once it's demonstrated the effectiveness of these general concepts, the second part is about the construction systems that respect these concepts. These construction systems will allow us to build this smart public space for the city. This reflection is a regard of the public space construction from another point of view, thanks to the seed and the concern that others have cultivated and shared before. Bases for the research:First of all I'll define some general concepts, which are the foundations of this article. The first concept, "Public space" has been considered as open areas ,at least, in one of the sides of their enclosure, accessible to all residents and users ; spaces of public use and domain. A second basic concept is "sustainable development" : Dr. Gro Harlem Brundtland, described "sustainable development" in the Brundtland Report (1987) as a process of change in which the exploitation of resources, prioritization of investments, the orientation of technological and the institutional reinvention match the present and future social needs. Thus, the combination of two concepts "sustainable construction of public space", is based on the following principles (based on the criterion of Kibert, 1994