Greening cities: professionals are ready

A consultation that gives a voice to architects, landscapers and engineers

Understanding what was the feeling of building prescribers faced with the challenges of revegetation and soil permeability (do they feel ready or helpless?) Were the main objectives of the survey.

A wide range of architects, landscapers, structural and VRD engineers, etc. was invited to describe his desires and projects in terms of revegetation via mostly open questions, the artificial intelligence of Talk4 ⁽¹⁾, then making it possible to process and synthesize the 3412 contributions and 4402 ideas produced by the participants.

Lessons from the study

According to the study carried out by Talk 4 on behalf of ECOVEGETAL ⁽²⁾, it appears that, for 24% of respondents, the durability of permeable car parks would represent a brake, compared to 21% for whom permeable car parks would entail additional maintenance costs. As such, for 20% of the people questioned, the interview would be an obstacle to their development.

Conversely, green roofs do not raise questions about their durability but rather about the additional costs that they could generate for 28% of the people questioned against 17% of them who evoke the problems of upkeep, maintenance. and related costs. We will note that 12% of the people questioned think that the weight of the green roofs would be a brake or even that this technique would require load calculations which they do not master.

For the installation of permeable car parks, 38% of specifiers opt for permeable green car parks, against 34% for gravel / crushed stone and 9% for natural stone. Extensive green roofs ⁽³⁾ are prescribed by 36% of respondents, ahead of semi-intensive green roofs ⁽⁴⁾ which hold the attention of 24% of architects and landscapers.

For 23% of respondents, good rainwater management, good permeability, filtration, drainage and the ability to absorb runoff water are synonymous with successful permeable parking.

The expectations of 13% of those questioned, in terms of green roofs, relate to the right choice of plants, technical mastery and good training. 11% mention thermal comfort on par with aesthetics and the good integration of the roof into its landscape.

20% think that a rich biodiversity, a good integration into the landscape constitute the decisive elements to affirm that a green roof is successful or not. For 15%, it will be more a question of associating the notion of low and easy maintenance; ahead of 12% who think that water retention, watering and irrigation are essential to obtain a perfect green roof. The installation itself comes in fourth place with 10% of the responses.

For Pierre Georgel, CEO of ECOVEGETAL: “Lack of awareness of the benefits of revegetation is still an obstacle to its development today. We will have to explain with perhaps more relevance, the advantages and the costs compared, compared to coated surfaces for example. On the other hand, I also see that 66% of respondents have already prescribed green roofs and that 70% prescribe permeable parking lots ”.

For Pierre Georgel: “Greening represents a real underlying trend that could take root when we see that, among those who prescribe it, half already do so for more than 20% of their projects. Better still, the latter associate permeable car parks and green roofs with the words biodiversity, pollinating insects and places of life. We have made progress. It's undeniable " !

⁽¹⁾ Talk 4 is a company that designs tools for dialogue in the company and study in the broad sense. Talk 4 carried out this study in May and June 2021 with more than 700 architects and landscapers

⁽²⁾ ECOVEGETAL is the leading company in permeable car parks in France with more than a hundred projects and co-leader of green roofs. ECOVEGETAL employs 100 people divided between the head office located in Eure-et-Loir, in Broué (28), and three production sites in France: Le Thor (84), Poussignac (47) and Seraucourt-le-Grand ( 02)

⁽³⁾ An extensive green roof is an inaccessible roof using an elaborate cultivation complex of low thickness and whose maintenance is reduced to a minimum. An intensive green roof is an accessible green roof of the garden terrace type.

⁽⁴⁾ A semi-intensive green roof is located halfway between the two scenarios mentioned above