Extensively flat green roof that transitions to a steep slope. To keep the substrate in place, we installed drainage plates with high ridges. In these ridges, the substrate stays in place and there is no risk of leaching. For an immediate end result, we choose pre-grown sedum mats that are pinned with small pins in the substrate, in such a way that the sedum mats cannot roll down. Over time, the sedum mats take root in the substrate and the pins are no longer needed. A fun but especially beautiful end result!