In Paris (12th), the Saint Antoine AP-HP hospital can be considered a real city within a city. Respect for the existing environment, preservation of views and optimal and flexible functionality over time are all factors that have guided the choice of location and volume. The new headquarters of the Paris hospitals is compact, does not affect the luminosity of the neighbouring buildings and frees up a planted core equivalent to 50% of the plot of land.
This garden recreates a hilly landscape covering the amphitheatre located in the base. Creating a square, a space for exchange, surrounded by trees, this planted alcove gradually reveals itself as visitors move through the site, offering soothing views to users of the buildings that border it.
Designed to increase the permeable surfaces and accentuate the planted landscape continuity, the garden offers a palette of plant species native to the Ile-de-France region, grouped according to four distinct biotopes that complement each other and each contribute to the development of local biodiversity: mixed woodland, wet meadow, shrubby forest edge, and mesophilic meadow. The amphitheatre is located under this new landscape topography, under a thickness of soil varying from 50 to 250 cm. In addition to the garden, the roof of the building is entirely planted. The plant layer is made up of resistant species requiring little watering, and the thickness of the soil here varies from 20 to 60 cm.
The continuation of our research on how to host life in architecture finds a new application here through the development of a living concrete wall , designed in collaboration with the general contractor CBC and for which a patent has been filed. In continuity with the garden, this perimeter wall with a surface area of 390 m², made of prefabricated panels, surrounds the auditorium that carries the hill.
This concrete facing is fixed at a distance from the structural wall to provide sufficient space for the substrate earth. The plants spread their roots in this thickness and grow through the cavities in the façade. The plant community chosen for the wall tended towards native, resistant species. Depending on the orientation and humidity of the wall, we favoured certain muricolous species – known to thrive on old walls – or herbaceous undergrowth.
annex: Hosting life, architecture as an ecosystem
The city-nature connection is of particular interest to ChartierDalix, which, through its Research and Landscape departments, has been working for several years on the integration of life and biodiversity in architecture and landscape. The first research is collected in a book entitled “Hosting life: architecture as an ecosystem” published in 2019 by ParkBooks.
The biodiverse wall is a new type of vertical vegetation system designed to promote biodiversity in dense cities by hosting local and indigenous fauna and flora. Rather than a vertical garden generally composed of exotic plants, the inhabited wall offers a unique architectural quality, which gives the opportunity for plants to settle sustainably and in a more autonomous way than hydroponic wall systems.
What sets it apart from existing green walls is the continuity of the substrate network within the wall – from the soil at ground level to the roof garden – which acts as a reservoir of water and nutrients for the plants as they grow independently. Like a garden, this structure helps to reduce the heat island effect, absorb pollutants, cool the air through plant evapotranspiration and absorb rainwater.
This system is the result of ongoing research developed by ChartierDalix for over 10 years. Several biodiverse walls have been built using other materials, such as dry stone and brick, and are constantly monitored and evaluated by scientists and ecologists.
This is the case of the Greater Paris Metropolis Pavilion, built in dry stone for the Versailles Architecture and Landscape Biennale in 2022, and a pavilion built in Paris in 2021 made up of several 1:1 scale prototypes1 (single-wall brick, solid brick, dry stone), the ecological monitoring of which is the subject of the thesis by Delphine Lewandowski, a doctoral student hosted by the office from 2019 to 2023. Finally, a last experiment involves the construction of a pavilion on an urban farm in 2024. It features a façade system made of reused wood modules, assembled and embedded to create platforms to support the substrate and flora. These different projects are presented in the images file.
• Other credits:
– AP-HP (client)
– Experimental “living concrete wall” created in partnership with the contractor CBC (subsidary of Vinci Construction) as part of a more global research on biodiverse walls carried out by ChartierDalix for more than 10 years.
– Landscaping project carried out in collaboration with the Atelier d’Ecologie Urbaine, an environmental consulting and design firm led by Jean-Louis Ducreux (a PhD in applied geology, geotechnician and specialist in functional ecology).
– photo credits: ©camillegharbi
