The massive use of plastic in our daily life is a real stake in which the main consequence is maritime pollution under macro-waste (materialization of a “seventh continent” in the middle of the oceans). Besides, the global warming risks to cause in years from here a sea level rise with dramatic consequences : the loss of soils for islanders, a potential migration of all these populations. This project aims to benefit from all the physical an chemical properties of plastic (low density, low temperature of transformation, elasticity, anticorrosion, low thermal conductivity) and its large presence in the ocean in the form of macro debris in order to use it as a key construction element in the cycle of living systems. Thanks to an oceanic navigating modulator, polluting plastics are recycled under the form of modules looking like alveolus. Those modules are then aggregated to create a new floating substrate and fit to serve as devices, welcoming vegetal matters useful to develop agriculture, desalinates sea water and permits the building of livable spaces