The renovations initiated by UNESCO involve Building V, designed by architect Bernard Zehrfuss and engineer Jean Prouvé, as well as the gardens designed by André de Vilmorin. The landscaping is carried out in harmony with this pre-existing architectural style, which is simple and rigorous. The institution’s entrance, visible from the street, has been reimagined as an esplanade with a unified granite base, typical of Paris. The existing trees are complemented by new plantings, lending the space a more wooded character. The lawns have been replaced by ferns, evoking a woodland landscape. This new communal space for the institution’s employees is designed as a micro-clearing where movable tables and chairs are available. The four patios of the main building serve as light wells for the offices and feature densely planted naturalistic gardens, resembling a miniaturized natural landscape. Green roofs complete the ensemble with thermophilic grasslands that help combat heat islands and promote sustainable stormwater management. Lightly vegetated, they require little maintenance and are adapted to structural constraints and sunlight conditions.