To built in an easily flooded zone, a friendly and a warm edifice in an HEQ way of thinking while assuring the safety of the site and the longevity of the project.site, brief and project /The project takes place along the boulevard. It is used as an acces filter for the tracks thanks to its openwork envelope. The fence on the boulevard uses the facade system and improves its presence on the way while developping a kinetic effect when you are driving all along the building.The building skin is constituted of vertical elements, made of strips of timber or metalic slats, regularly spaced according to their function. The envelope was made in order to solve all the constraints depending of the brief and of the site : solar protection, intimity, modularity of the building, prefabrication, anti-intervention, anti-vandal, environmental approach…Building & sustainable development /Simple and rigorous volumes allow the optimisation of the way of building, the rationalization of the structure, of the envelope and of the networks.Implementation of windbreak hedges composed of local species with persistent foliage. Preservation of the existing vegetation. Development of a biodiversity in relation with the site (humid environment). The drainage ditches allow to rid the water of pollution thanks to a system using plants.