The portal for recovery of building materials.

Today, there are more and more companies specialised in dismantling and reusing materials from construction and renovation projects. They are committed to anchoring reuse in current building practices. It is essential that their efforts and presence on the market become visible so that they can connect with the current and new generation of professionals.

That is why Rotor vzw already created the website Opalis.be in 2011: an online platform where contractors, architects and building owners interested in used materials can find each other. It includes an overview of available dealers, materials and other practical information about the (re)use of building elements.

Initially, the inventory was limited to companies in and around the Brussels Capital Region, but in the meantime the website has been expanded to include dealers from all over Belgium, as well as sample projects with reused materials. With the support of Circular Flanders, we want to expand our project again, with 2 focus points. On the one hand, we want the list of traders and example projects to grow even further. In doing so, we want to look for less obvious companies and for projects with reused materials of which we have no or few examples.

On the other hand, we want to prepare the platform for a large European Interreg-project, in which we want to extend the research into reusable building elements across national borders, together with 7 other partners.


  1. Opalis' current list of traders was thoroughly updated and we started looking for new traders to add to the platform. We focused on less obvious companies to diversify the website and broaden our overview of the sector.
  2. We documented additional example projects with reused materials. We focused on projects with less traditional materials of which we had few or no examples, and projects by the most prominent Flemish traders.
  3. We made the necessary preparations for cooperation with seven other partners in a major Interreg project. Its main objective is to increase the amount of recovered building elements in circulation by 50% by 2032.
  4. We have put extra effort into communication. We organised a study day that brought together the various players in the reuse sector. Traders could express their views on the opportunities and limitations they currently experience, and on the future of the sector.


  1. Traders have difficulty accessing materials that are interesting for recovery, as they often have to be collected as quickly as possible. Promoting recovery-friendly demolition (or making the recovery of certain popular re-use materials obligatory) could improve that situation.
  2. Traders find it more difficult to deliver to large construction projects than to private individuals. The bigger the project, the longer the period between material selection and delivery. If the chosen material is just not available at the time of execution, this can lead to practical and legal problems.
  3. There is too little overlap between the demand for materials and the supply. Contracting authorities have been using the same specifications for years, so they keep asking for the same materials. There is a need for more flexible descriptions of materials in those specifications. For example: for cobblestones, only specify the type of stone, and not the size.
  4. Traders need a material certificate specifically for reclaimed materials, a kind of 'truly reclaimed' label. Such an alternative label would guarantee high-quality recovery (not stolen, correctly dismantled, sorted and packaged, etc.) and give clients more confidence in choosing these materials.
1 clear platform
121 traders from Belgium
68 sample projects
50% more reused material by 2032


Since 2019, we have been making many preparations for a major Interreg project. The main objective is to increase the amount of recovered building elements in circulation within the project area by 50% by 2032. To achieve this, in the coming years, together with 7 other partners, we will work on 3 sub-objectives: expanding Opalis throughout the Benelux and France, developing the necessary technical and legal information for the extraction of reusable materials and for the integration of these materials in new construction projects, renovations and alterations.

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