Nature Based Solutions - Implementation Models Database
Green roof of the Aimé Césaire school complex
A short description of the NBS project
The school is located at the west of the "Ile de Nantes". The building in (R+1) is designed around courtyards and interior terraces. This project is notably characterized by the originality of its green roof (1) resulting from a co-construction between architects and landscape designer. Its qualities are undeniable, and this project has received several prizes. Two main original aspects characterize this green roof:
the accesses: two ramps allow direct access to the roof from the ground floor courtyard
the vegetation: the project involves the establishment of dunes and moor vegetation. Its design is based on a technical work dealing with the treatment of slopes, the nature and thickness of the substrate, and the research of plants.
The objectives of the intervention are to:
-Reinforce the insulation of the building (acoustic, energy efficiency)
-Favor urban 1
-Limit the intensity of management
-Propose a pedagogic support
NBS Implementation context
Description of the NBS
object (building, etc.)
NBS Impacts scale
object (building, etc.)
Urban density/ Soil consumption
Combined with other(s) environmental friendly solution(s)?
A public institution, a local organization (city or metropolitan)
Project manager (leader and main partners): entities names, and know-how involved
Leader: B. Mader (architecture)
Main partners: Mabire & Reich (Architecture) & Phytolab (Landscape architecture)
Who (else) was involved in the project ? (Inhabitants, local association, etc.)
A quite classical public tendering process.
More detail on the process and the role of the different stakeholders (How did it happen?)
The city green spaces services has been involved in the monitoring and the management of the green roof. Their objective was to adapt their pratcises to the specific employed vegetation. The conservatory has been involved in the monitoring of the vegetation, and for its development as specific ecosystem.
OPTIONAL Considering the actual impacts, who are the primary beneficiaries of the project.
The governance model is centralized around Nantes Métropole
Global Estimated cost of the project
Description of the financing mechanism
The project has received subsidies from the Pays de la Loire region regarding the R&I for the vegetalization
Substitute with renewables and natural processes
The conception of the green roof is based on a deep understanding of the ecologic characters of plants. The choice of species is especially well adapted to rude conditions met on roofs (wind, lack of water). It targets to limit as much as much the management interventions.
Expected time for the NBS to be fully effective after its implementation
short (immediately to few months)
Expected life time of the intervention
around 25 years
Already feedbacks on the project? In case, the project has already been adapted to new requisites, please explain the modifications brought
Success and limiting factors
1° The project got benefits from the collaboration with the municipality green space services (future manager), and from the regional Natural Space Conservatory. They both have been integrated in the conception of the project.
2° The co-conception between architects and landscape architects
Dune and moor plants are not commercially available.
What makes this project a pioneer?
Brief description of the innovativeness
1/ The choice of plants based on poor ecosystems (dune and moor) is well adapted to hard conditions (wind, drought) met on roofs. It allows a sparing management.
2/ The design of the building - with 2 access ramps- facilitate the social uses of the roof.
3/ The in-depth researchs on vegetation and the works on slopes reach 1 criteria.
Has the project received a prize, an award?
"Victoire du paysage" in 2014 (national level)
Has the project received a media coverage? (in reviews, in press, etc.)
Saint-Pierre Raphaëlle, 2014, Une école-paysage en bord de Loire, Le Moniteur, N° 5758.
Bailly Delphine, 2014, Ecole buissonière -Groupe scolaire Aimé Césaire à Nantes, EK EcologiK, n°37, pages62-71.
Mareschal Loic (Phytolab), 2015,"Ecole paysage -Schule mit Landschaft", Bâtiments végétalisés - Grün und Bau, Anthos,pages 48-51.
Websites of conceptors:
SAMOA website (Société dAménagement de la Métropole Ouest Atlantique):
Presentation of the projet by L. Mareschal (Phytolab), Ph. Férard (Nantes Municipality) et D. Lafage (Natural spaces conservatory of the Pays de la Loire), Work journey "Capitale française de la Biodiversité" , March 2017, Nantes Métropole