“Invisibility” is the theme of the projects submitted for the competition “Two houses on Selvagens Islands”. After reviewing the competition’s program and all the environmental restrictions of the landscape, any building proposed for the ecological paradise of Selvagens, should be invisible, somehow diluted on the landscape, as if it didn't exist, or have always been part of the place’s geography. Pointed the theme, some questions concerning the difficulty of construction logistics and the lack of local transport for materials should be gently pondered and questioned. Through a theoretical and reflective exercise of architecture, the desire of experiencing two constructive systems was born, one for each house, both with the same purpose and main concept - the “Invisibility”. The location proposed for the house at Selvagem Grande Island, its geography and topography, pointed to a stereotomic architecture, where the force of gravity is transmitted in an uninterrupted way and the constructive continuity is complete.On the other hand, the barren and deserted landscape of the Selvagem Pequena Island, suggested a tectonic architecture, where the force of gravity is used on a structural logic of knots and joints. On this island, a gentle constructive system made all the sense, a kind of light and slight architecture, almost immaterial. In conclusion, two places, two languages, two architectural approaches, worked and designed pursuing the same theme and objective - the “Invisibility”.