Urban building lands are considered a scarce resource, which forces us to rationalize their use and assignment. They play an important role in shaping the urban space with all its components and determine its characteristics. The impact on urban space depends on the legal nature of the land, the density of buildings, and the quality of social cohesion. Like all Algerian cities, the city of M'sila has experienced, since the '90s, an increasing demand for building plots, especially in the outskirts which are mostly private properties. This situation directly contributed to the spread of illegal constructions and as a result, districts lack basic living conditions. This phenomenon appeared in the peripheral district called La Rocade. In this paper, we will attempt to identify the impact of the legal nature of land properties, particularly private ones, on the proliferation of illegal constructions in the outskirts of the city of M'sila. We will try to find solutions and alternatives to limit or stop its spread and propose urban interventions to restructure this district and integrate it into the existing urban space.