Permeable pavement, clay soil, general water management

A little update here. We have solved it like this now

Not flush, but with a full row. It gives more room to work and saves a few cut pieces. When the paths are paved in the fall, we'll connect to it. For now, there's only the small entrance area so you can wipe your dirty shoes. During the paving work, the rest of the site will be raised a bit as well, so we can then enter the house barrier-free (just in time as the stroller phase slowly comes to an end...)
Pro tip: install the grids in the channel before paving, otherwise it compresses and the grid only fits back in with force ;)

Also, we learned a valuable lesson during that time. A roof offers no protection in doubtful cases. We had a thunderstorm two weeks ago, and it was pelting head-high against the patio door. So despite the roof, you shouldn't skimp on the slope

You mean the horizontal row on the right? I hadn't planned that so far, but it wouldn't be such a big job to chisel away the concrete underneath