Green Roofs UP!
With the support of the Innovation & Enterprise Agency www.vlaio.be
Green roofs are very widely applicable and the demand for green roofs has risen sharply. A logical consequence of this is that several companies have jumped on the bandwagon of this green roof 'revolution' in recent decades. The green roof industry reports that the green roof revolution has led to a strong fragmentation of available knowledge. There is no longer uniformity in terms of materials, no overview and too little quality control of the products on the market, the existing guidelines are outdated and leave too little room for innovation.
A second problem is that people often opt for the cheapest solution, namely an extensive green roof with succulents on the thinnest possible layer of substrate. This system certainly has its place in the market offer, especially when the load-bearing capacity of the building is limited. In the context of climate-robust cities, there are alternative green roof systems (e.g. thicker substrate, more biodiversity) that offer more pronounced advantages, especially in terms of water collection, temperature mitigation and particulate capture!
Last but not least, the green roof sector also questions the sustainability of its own materials. For instance, the substrate consists largely of porous rock (often lava rock) from Germany. This a) cannot be called sustainable because the material is not mined locally and is therefore more expensive and b) there is a threat of imminent depletion of the quarries. So there is an urgent need for alternative, local materials for use in green roof substrate, which preferably also fit within the narrative of the circular economy. 
The overall goal of the GREEN ROOFS UP! project is to bring about a transition that will ensure more quality, uniformity and innovation in the green roof sector. We want to achieve this with maximum cooperation and exchange of existing knowledge and expertise with the sector.
Green roofs are very widely applicable and the demand for green roofs has risen sharply. A logical consequence of this is that several companies have jumped on the bandwagon of this green roof 'revolution' in recent decades. The green roof industry reports that the green roof revolution has led to a strong fragmentation of available knowledge. There is no longer uniformity in terms of materials, no overview and too little quality control of the products on the market, the existing guidelines are outdated and leave too little room for innovation.
A second problem is that people often opt for the cheapest solution, namely an extensive green roof with succulents on the thinnest possible layer of substrate. This system certainly has its place in the market offer, especially when the load-bearing capacity of the building is limited. In the context of climate-robust cities, there are alternative green roof systems (e.g. thicker substrate, more biodiversity) that offer more pronounced advantages, especially in terms of water collection, temperature mitigation and particulate capture!
Last but not least, the green roof sector also questions the sustainability of its own materials. For instance, the substrate consists largely of porous rock (often lava rock) from Germany. This a) cannot be called sustainable because the material is not mined locally and is therefore more expensive and b) there is a threat of imminent depletion of the quarries. So there is an urgent need for alternative, local materials for use in green roof substrate, which preferably also fit within the narrative of the circular economy. 
The overall goal of the GREEN ROOFS UP! project is to bring about a transition that will ensure more quality, uniformity and innovation in the green roof sector. We want to achieve this with maximum cooperation and exchange of existing knowledge and expertise with the sector.
Resultaten
The GREEN ROOFS UP! project aims to stimulate a transition that will ensure greater quality, uniformity and innovation in the green roof sector. Both the companies and the urban climate and environment will be positively affected by the application of well-founded guidelines and increased knowledge about alternative green roof systems and more sustainable substrate materials. Knowledge exchange between companies and researchers is central to this transition.
The project included 3 major parts:
Thematic workshops with the green roof industry to provide the basis for updating the guidelines from the WTCB's TV229 (2006)
Search for potential alternatives to the mineral portion of green roof substrate.
Demonstration of green roof systems in the context of climate proofing
Illustration of the results obtained:
Final report part 1: advice on different themes: green roof systems, vegetation, substrate, maintenance, flat roof construction, roof finishing and leak detection. Each theme ends with some concrete recommendations that can be included in the updated TV229.
Final report part 2: Besides the technical characteristics of classic substrate material and the motivation for the selection of 4 alternative materials (WTCB), this document also includes an LCA study of the green roof substrates (WTCB), which shows that transport does have the greatest environmental impact and that it is therefore certainly important to look for local alternatives. Finally, this report contains the market study in which the demand, supply and price of all selected materials were examined (UHasselt).
Final report part 3: this report covers the construction of the demo roof on the Corda Campus in Hasselt, as well as the methodology and the results of the vegetation surveys. In addition, this document includes an overview of different calculation tools, useful to check the effect of green roofs on the climate resilience of cities.
Next to the final reports we mention the project website www.greenroofsup.be, where information from the project was collected and where the final reports can be found.
The project results were presented in September 2022 during the DAKkan festival and Green Expo 2022.
The project did trigger a transition. In recent years, we have noticed a growing interest in the importance of greenery in cities, and in and around buildings in general. On the one hand, cities and municipalities are asking for more concrete information around green roofs, in order to provide targeted advice and make decisions in the interest of improving climate resilience in the built environment. On the other hand, the sector itself is also looking for unambiguous information and more verifiable quality. A number of points of attention came to light throughout the project, and these can now be built upon further. An example of this is the need for certification/quality requirements for green roof substrate. There is also a need for an obligation for green roofs with specific quality requirements. In construction projects, people still choose the green roof systems (and the company that installs them) with the lowest price, and therefore also the lowest quality. For this reason, the cooperation of the authorities in this project has also been of great value. They effectively see the need for quality requirements, and will take this into account in their specifications, etc. The fact that WTCB will effectively use the recommendations to renew TV 229 keeps the transition we initiated going.
The project included 3 major parts:
Thematic workshops with the green roof industry to provide the basis for updating the guidelines from the WTCB's TV229 (2006)
Search for potential alternatives to the mineral portion of green roof substrate.
Demonstration of green roof systems in the context of climate proofing
Illustration of the results obtained:
Final report part 1: advice on different themes: green roof systems, vegetation, substrate, maintenance, flat roof construction, roof finishing and leak detection. Each theme ends with some concrete recommendations that can be included in the updated TV229.
Final report part 2: Besides the technical characteristics of classic substrate material and the motivation for the selection of 4 alternative materials (WTCB), this document also includes an LCA study of the green roof substrates (WTCB), which shows that transport does have the greatest environmental impact and that it is therefore certainly important to look for local alternatives. Finally, this report contains the market study in which the demand, supply and price of all selected materials were examined (UHasselt).
Final report part 3: this report covers the construction of the demo roof on the Corda Campus in Hasselt, as well as the methodology and the results of the vegetation surveys. In addition, this document includes an overview of different calculation tools, useful to check the effect of green roofs on the climate resilience of cities.
Next to the final reports we mention the project website www.greenroofsup.be, where information from the project was collected and where the final reports can be found.
The project results were presented in September 2022 during the DAKkan festival and Green Expo 2022.
The project did trigger a transition. In recent years, we have noticed a growing interest in the importance of greenery in cities, and in and around buildings in general. On the one hand, cities and municipalities are asking for more concrete information around green roofs, in order to provide targeted advice and make decisions in the interest of improving climate resilience in the built environment. On the other hand, the sector itself is also looking for unambiguous information and more verifiable quality. A number of points of attention came to light throughout the project, and these can now be built upon further. An example of this is the need for certification/quality requirements for green roof substrate. There is also a need for an obligation for green roofs with specific quality requirements. In construction projects, people still choose the green roof systems (and the company that installs them) with the lowest price, and therefore also the lowest quality. For this reason, the cooperation of the authorities in this project has also been of great value. They effectively see the need for quality requirements, and will take this into account in their specifications, etc. The fact that WTCB will effectively use the recommendations to renew TV 229 keeps the transition we initiated going.
01/10/2020 - 30/09/2022
