UNESCO (United Nations for Educations, Science and Culture Organization) launch a rehabilitation operation of its site welcoming permanent delegations of the institution in the XV arrondissement of Paris. It is about a prestigious site with a strong architectural legacy.

The renovations mainly aim at restoring building V, conceived by the architect Bernard Zehrfuss and the engineer Jean Prouvé between 1966 and 1969, as well as the gardens designed by André de Vilmorin. While Zehrfuss find his inspiration in the composition of the historical site of UNESCO (Fontenoy site), in which he is also implicated, by adding one more time four patios to the building, Prouvé conceives un metallic structure, remarkable piece that constitute the identity of the building.

Building V is currently composed of a lower part holding a cafeteria, parking and other equipment, and an upper part of eight levels of offices provided for the delegations of 110 country. Today the site features strong constraints: it is landlocked and the numerous circulation flow gestion prevents the creation of a peaceful living places for the institution’s employees. Its landscaping is mostly very mineral, including its gardens with little vegetation.

The project plans to address the site malfunctioning and to improve the ecological durability of the building as well as its quality for users, whilst guaranteeing the preservation of the architectural legacy. Landscaping will be realized according to the simple and rigorous architectural writing that highlight the prestigious nature of the organization.

The entrance to the institution, visible from the street, is largely redefined. First of all, the constraints of car access and pedestrian circulation have been fully reconsidered. The access ramp to the underground parking lot has been maintained and the drop-off area has been transformed into a real forecourt. The entrance esplanade is designed as a unitary granite base, a typically Parisian floor. The existing trees are reinforced by new plantations bringing a more forested character while the lawns are replaced by ferns. Lawns are replaced by a set of ferns to recall an undergrowth landscape.

Through these transformations we propose a more interesting ecologic environment but also that needs less maintenance. The adjoining walls located on each side of the garden will be covered by climbing plants. The space dedicated to bikes is extended to meet user’s expectations.

The requalification of the entrance concerns in a second step the transformation of a wasteland into a garden. This new place of life intended for the employees of the institution is conceived as a micro clearing in which tables and mobile chairs at disposal allow the appropriation of the garden.

The four patios of the main building function as skylights for the offices. They are little planted, fairly built and no use have been assigned them except for the patio number 2 that welcomes the cafeteria’s terrasse. Their vegetal composition will be enhanced et some built elements such as low walls will be erased. Each patio will recall a miniaturize natural landscape: naturalists gardens densely planted, without any formal composition and evoking an undergrowth atmosphere.

The project includes the installation of thermophilic grasslands on the rooftops. These grasslands help to reduce the urban heat island and allow for a virtuous management of rainwater. Lightly vegetated, they require little maintenance and are adapted to structural constraints and sunlight conditions.