The design I'm starting with is very simple; 10 feet wide by 4 feet tall cube of PVC and a 16x20 foot tarp designed for this use. Four 4 foot tall corners, two 4 foot tall supports in the middle, and then four 5 foot long pieces for the length. Everything is Schedule 40 PVC with 3-way corner T's on the corners and 3 way T's in the middle for support. I plan to secure the corners with screw-down tent pegs and currently do not plan on glueing or screwing any of the corners to make it easy to disassemble and store but that may change based on how secure the structure is in use. I have not yet decided how I am going to secure the tarp to the structure itself, but I know in general I'll have the rear and sides mostly fixed in place and the front panel I can lift to water and tend to the plants.
The UV tarp I had picked out is unfortunately out of stock before I got around to purchasing it, but I'll be watching for it to come back in stock or over the winter or I'll find another. The one I had picked out was UV safe, had good reviews to stay flexible after being used for a few years, and it was thick enough to not worry about it ripping.
I plan on putting it out once the temperature is well above freezing in the Spring, basically as soon as I can get veggies at a store, plant them in the garden, build the greenhouse around them, then secure the tarp around the structure.
Ideally, I would start my plants from seed or small plantings indoors and avoid having to depend on when the local stores get plants in stock. However, I'm not sure if I'll be able to do this as I don't have a lot of window room (all of our window sills are rather small) and our cat is fascinated by plants and will likely eat them.
Hopefully, it'll keep itself warm enough for the plants to establish themselves and possibly start growing, I will just need to keep them watered. I do not currently plan on heating the greenhouse from inside, hopefully, the sun will be enough to keep everything warm and secure. Once it's warm enough I'll remove the tarp and perhaps leave the structure for a while just in case we get an overnight freeze and when there are no more chances of freezes I'll disassemble the PVC structure and put it away for the next year.
Storing the structure is only 10 1" by 4-5' pipes and some T's and the tarp so it should all store in a corner pretty easily. And hopefully, more veggies earlier in the year!
I will update with pictures once I add the middle supports and the tarp and pictures of the overall structure once in place and of course if I think it did the job.