The Opalis website targets architects, private individuals and contractors who wish to buy and sell reusable materials. Interested parties can see a detailed overview of the range of building materials from professional traders.
Opalis is a Rotor initiative. This non-profit organisation was founded in 2005 and uses various projects to examine how to reuse works across various sectors. In a series of studies into the construction sector, Rotor found that there was a range of options in relation to using recovered materials, but that the professional players in Brussels were not really using them, also that a great many potentially-reusable items were leaving Brussels sites without passing through the hands of traders. Opalis aims to bring suppliers and buyers closer to one another.