Innovative greening of the Respiro building

  • Year of commitment : 2015

  • Green energies : Energy Efficiency
    • Label/Certification :
      • HQE Infrastructures

  • 145 000 €
  • Builder

Located in a dense urban area, in Nanterre (Hauts-de-Seine), the office building in the Respiro building has benefited since 2015 from the greening of its two roof terraces covering more than 1,500m² in total. These roofs form a set combining extensive and semi-intensive ecological vegetation based on simple technical solutions.

The project, developed in partnership with the National Museum of Natural History, aimed to set up vegetation in favor of biodiversity, a WildRoof roof - we let the wild flora colonize the bare substrate - as well as free access to vegetable gardens.

Topager ensured the design, construction, maintenance but also ecological monitoring.

On 860 m² in R + 2 , the terrace is accessible (concrete support) and visible from the workspaces. The native plants are installed in situ on a substrate 8 to 25 cm thick. The appearance of semi-natural meadow varies throughout the year.
This vegetated terrace is inspired by the ecological functioning typical of dry meadows: diversity of plant layers, micro-habitats (eg mounds, ponds), no fertilization or amendments, no chemical treatments. Maintenance is limited to selective manual weeding on a monthly basis: thus the degradation of plants enriches the substrate and the dissemination of seeds renews annual plants. Watering is limited and localized on part of the green roof.

On the ground floor, on 650 m2 of steel bins, wild flora colonizes the bare substrate (WildRoollf® principle). Shelters for wildlife have been installed.

Progress Status


Data Reliability

3rd part certified

Funding Type


Website Enterprise / Infrastructure

Sustainable Development

    Activities to raise awareness of the biodiversity present on the site are carried out with the employees who occupy the building.

    In the same way that we exchange more easily with people that we meet in the forest rather than in the city, meetings on the biodiversity roof allow informal exchanges between the employees present on site in a more convivial setting.

    The project was designed from the start as a tool for welcoming biodiversity. Specific arrangements (nesting boxes, insect hotels, ponds, etc.) have been created to promote its development.

    The ecosystems created on this building are particularly resilient due to their diversity and complexity. They thus provide increased performance for the building's resilience to climatic hazards: natural cooling, rainwater management, protection of biodiversity.



    Private Company


    Construction Industry


    The economic model of the project is based on an initial investment of 145 k € as part of the renovation works with a 40% subsidy from AESN.

    For 6 years, the project has been maintained and monitored by Topager teams, at the expense of the tenants of this tertiary building who benefit from the services linked to this revegetation.

Sustainable Solutions

    Biodiversity in green roofs

    The roof has been the subject of various ecological monitoring. The most recent, carried out by the Ile-de-France Regional Biodiversity Agency (ARB IdF), dates from October 2020. As part of its GROOVES study (Green ROOfs Verified Ecosystem Services), 107 different invertebrate species including were identified, the maximum identified during this naturalistic monitoring carried out on more than 30 green roofs in Ile-de-France.

    This project was also subsidized by AESN for the good management of rainwater.

    • Water management
    • Management of natural areas
    • Climate adaptation

Photo credit


Reasons for participating in the competition(s)

  • Innovative approach to greening the building
  • Provision of ecosystem services in situ
  • Set combining extensive and semi-intensive ecological vegetation based on simple technical solutions

Building candidate in the category

Grand Prix Infrastructure Durable

Grand Prix Infrastructure Durable

Green Solutions Awards 2020-2021 / France

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    Green Solutions Awards 2020-2021 / France