This is my next nemesis : routing the conduits to my basement while keeping as much as possible of the 12cm foreseen for the slab. It’s an old staircase when they still needed to shovel coal in the basement. At some point someone closed it roughly with some prefab slab. So clearance is limited if I want to keep it as is and not take it apart (which would be… a long and shifty process). I’m currently missing about 3cm. I’ll see this week if I can grind them somehow.