Drainage channel under the roll layer?

Hi!

We will pave our terrace under the wearing course, so not at ground level. Would you still install a channel below the wearing course? If yes, would a simple infiltration system with KG pipe and gravel be sufficient, or should it already be connected to the sewer?

Thanks for your help

As long as you are sufficiently below the threshold so that no standing water pushes through the terrace door and you have a slope away from the house, I would skip the gutter.