Contact a green roof expert
Make your roof practical, durable and high-performing. We support you every step of the way, from feasibility to completion.
Are you planning a green roof for a new build or a renovation?
Demetair supports professionals, local authorities and project owners in implementing solutions tailored to the constraints of existing buildings. Based in Toulouse, our team operates throughout France to assess the feasibility of your green roof project.
What if your roofs could be put to good use?
Let’s work together to bring plants back into the city.
FAQ
In this section, you can provide clear answers to the most frequently asked questions.
Greening walls and roofs offers numerous environmental and economic benefits, such as:
- Reducing urban heat islands: green roofs on buildings lower the ambient temperature by absorbing heat and releasing it into the air.
- Improving air quality: plants absorb harmful gases and fine particles from the air, thereby helping to improve air quality in towns and cities.
- Reducing energy consumption: greening walls and roofs provides natural insulation that can reduce energy consumption for heating and cooling in winter and summer.
- Reducing energy consumption: greening walls and roofs provides natural insulation that can reduce energy consumption for heating and cooling in winter and summer.
- Promoting biodiversity: green spaces provide a natural habitat for insects and birds in urban areas, thereby helping to preserve biodiversity.
- Improving the urban landscape: greening walls and roofs can enhance the aesthetic appeal of the urban environment, providing a more pleasant living environment for residents.
- Reduced maintenance costs: green roofs require less maintenance than conventional roofs, thereby reducing maintenance costs.
Greening walls and roofs can also offer economic benefits, such as the creation of new green spaces in urban areas, increased property values and reduced energy costs for buildings.
A green roof is a system comprising a technical structure (waterproofing, drainage, substrate) that allows plants to grow on a roof. It helps to improve rainwater management, thermal comfort and biodiversity in urban areas.
Every project is unique, and the cost of installing a green roof varies depending on a number of factors, such as the surface area and the specific characteristics of the building.
Please contact us for a detailed assessment of your project.
Maintenance depends on the type of roof.
An extensive roof generally requires 1 to 2 visits a year (weeding, inspection, light maintenance).
More intensive systems require maintenance similar to that of a garden.
Yes, greening is possible during renovation in many cases.
Traditional solutions are often constrained by weight, but ultra-lightweight substrates now make it possible to adapt projects to the load-bearing limitations of existing buildings.
A well-designed and well-maintained green roof can last for several decades.
It even helps to extend the lifespan of the waterproofing membrane by protecting it from UV rays and temperature fluctuations.
Yes, it must comply with professional standards (DTU 43.1, ADIVET guidelines, CSTB standards) as well as local regulations (local urban planning regulations, stormwater management).
Some local authorities encourage or require the incorporation of greenery in new development projects.
Watering is important during the initial establishment phase, whilst the plants’ root systems develop throughout the substrate. The nature of our substrate facilitates this process, but this initial phase should not be overlooked. Subsequently, careful plant selection and planting will help to minimise losses caused by water shortage.
We have developed the VGHolz growing medium to enable the cultivation of as wide a variety of plants as possible.
However, there are still a few limitations:
- Never plant plants with overly ‘vigorous’ root systems, such as bamboo or hazel.
- The thickness of the substrate chosen will also play a part in limiting the types of plants that can be grown. Indeed, as is often said, it is important to bear in mind that there are just as many roots as there are plants above ground. That is why you should not consider planting an oak tree on the roof.
- And of course, the final limiting factor is the roof’s load-bearing capacity. A young oak tree, sure, but what will you do with it in 10 years’ time?
- And finally, it would not make sense to plant plants on a mountain roof that cannot tolerate ice. (We do not supply winter protection netting.)
The success of a project depends on many factors: structure, waterproofing, drainage and vegetation.
Comprehensive support helps to safeguard the project, ensure its sustainability and optimise its performance.