You could place the top pieces at an angle instead of vertical like in the pic.
Or if you built something like this that had a slope to it, you could put polycarbonate on top. Or corrugated metal or fabric etc. You would just need the slope so that rain and snow wouldn’t settle on it.
SeikoAlpinist@slrpnk.net 3 months ago
I have never seen these before just now, but if I had them on my house, I would hang viney plants in baskets from them and let it grow in such a manner that it creates a canopy.