How to raise the density and enhance the quality of the urban landscape at the same time? At the top of the Belleville's area, an ancient playground of a social housing building is now occupied by a strange object, half garden, half space-ship. Nowadays the folded brass membrane shines like a rap clip, but it will be soon covered by a grass colored patina and the west façade will match more and more better with the vegetal roof. As a purpose it is a nursery, but for the neighbors it is a piece of landscape, built to become even more attractive day after day.

Could a land lock field appear to be open if we look it from the right side? The nursery is not visible from the street. A porch roof marks the entry which leads the people through a gallery under the buildings of the street. Once the children are inside, they forget about the wall of buildings they just past as they are standing on a space wildly open to the exterior playground. Then, the nursery spreads on one single storey, linked by boxes, lighted and structured by a shed. On this side, the façade is no more mysterious, the functions of these boxes are easily recognizable by the children : a rest room, a wearing area..

Does the green aspects of a building have to be exposed to the people? A compact shape, a very good natural lighting, an efficient covering, an important output of renewal air, materials scrutinized... The basics are ensured. The extras qualities are barely visible. Some are hidden technical skills like the motorized windows loaded by the night VN during the summer or the damp-proof dryer which keeps the building dry... The other ecological bonus of the building deals more with a clever approach of the site. The building is set on an existing parking, and the structure in kit form has been delivered through a sort of underground gallery. This light structure avoids to reinforce the current infrastructure. It is no more visible nowadays, but it saved a lot of money and grey energy. However the green rooftop is more iconic and it communicates about a couple of issues unknown by many people like the stormwater, the biodiversity, the inertia, the sprinkling and the urban 'heat island' effect. Last but not least, it is a good way to remind this strong and ancient link between nature and architecture, which at time creates nice things.