Nature Based Solutions - Implementation Models Database

Pioneer Case

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
Location France, Nantes
Latitude 47.204795
Longitude -1.56576
Status Project delivered
Dates 2012.0
Description of the NBS
NBS Scale object (building, etc.)
NBS Impacts scale object (building, etc.)
Urban density/ Soil consumption medium
Combined with other(s) environmental friendly solution(s)?
if other
NBS Typology
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NBS Uban Challenges
Climate Issues Climate mitigation
Climate adaptation
Other 0;
Urban water management and quality Urban water management and quality
Flood management
Other 0
Air Quality Air quality at district/city scale
Air quality locally
Other 0
Urban Space and Biodiversity Biodiversity
Urban space design
Urban space management
Other 0
Urban Regeneration and Soil Air quality at district/city scale
Other 0
Resource efficiency Food, energy and water
Raw materials
Other 0;
Public health and well-being Acustic
Quality of life
Other 0;
Environmental justice and social cohesion Environmental Justice: Recognition
Environmental Justice: Procedural Justice
Environmental Justice: Distributional Justice
Environmental Justice: Capabilities
Environmental Justice: Responsibility
Social Cohesion
Other 0;
Urban planning and governance Urban planning and form
Governance in planning
Other 0
People Security Control of crimes
Control of extraordinary events
Other 0
Green economy Circular economy
Bioeconomy activities
Direct economic value of NBS
Other 0;
Stakeholder and Governance
Who Started this initiative? A public institution, a local organization (city or metropolitan)
Contracting Authority Nantes municipality
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 pupils Teachers Municipality
Cluster Governance Model Description
cluster1_traditional_public_administrationThe governance model is centralized around Nantes Métropole
Global Estimated cost of the project 200k€- 1M€
Cluster cluster1_public_financing
FM Other
Description of the financing mechanism The project has received subsidies from the Pays de la Loire region regarding the R&I for the vegetalization
Business Model
Class Type Description
TechnologicalSubstitute with renewables and natural processesThe 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.
Temporal Factor
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
Process Enablers
Class Subclass Type Description
Knowledge_driversCollaborationNetworks1° 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
Process Inhibitors
Class Subclass Type Description
Knowledge_barriersTechnical_inadequacyLack_of_readytoapply_scientific_resultsDune and moor plants are not commercially available.
What makes this project a pioneer?
Field Design_or_techniques_employed
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.
IM Keywords
  • green roof

  • school

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