Nathan,
For the box design..
The walls could be permanently fixed to the balcony if need and the "convertible top" is a heavy duty UV tarp which is watertight.
It definitely worked during the trials....
Does that help??
The ROR has side flashing and end overlaps - I can get some photos if needed. This has given a 100% weatherproof solution - no water ingress during the recent VERY heavy storms.
Re Vermin.....good question.
This hasn't been an issue for me (so far) but the edge sealing could be improved using semi-rigid closed foam along the sides and on the roof end overlaps.
It's been working for me.....
