This article presents the partial results of more extensive research on the urban regeneration of neighborhoods entitled, "Replicable and innovative future efficient districts and cities" (CITyFiED). Specifically, this paper discusses the possibility of ecologically improving building surroundings through vegetation and the primary aim is to develop an overall treatment strategy for the surroundings of buildings that are in the process of urban improvement. To this end, the paper addresses the first stage in which the environmental benefits of vegetation were analyzed, and presents universal and generalizable parameters and criteria about the sustainable treatment of free space in neighborhoods. In the second stage, these parameters were applied to a specific case: the Torrelago neighborhood, located in the town of Laguna de Duero (Valladolid, Spain). Thus, the main preliminary conclusion of this research is that the treatment of the free space that surrounds buildings plays a determining role in urban sustainability.