After many years of dreaming, scheming and research on various forms of hoop house design and construction we got tired of "analysis-paralysis" and just did it the easy way (small, cheap and simple):
So how did we do it? Well, first we decided to solve a number of problems simultaneoulsy. We had some raised beds in the back part of our garden and that area had proven too wet so why not use the soil and boards from those raised beds to create the base and growing beds for our hoop house? We could then move the garden fence to just behind the hoop house and transform the back (wet) part of the garden into what it wants to be (wetland). Below is the completed base with part of the planting beds being solarized and part planted to long-season sweet potatoes. Behind that you can see some prominent yellow flowers - those are Jesrusalem Artichoke (Helianthus tuberosus) - great for pollinators, great for people (tubers are edible and delicious)!
Fast-forward and here we have the frame up, the ends framed and the door and window installed. The door was pulled from someone's trash, the window was re-purposed from our house, the plastic was a gift from our brother-in-law. We had to buy hardware and hoops. We opted for PVC to do the hoops to simplify the process. We don't anticipate strength issues as we are not in many-feet-of-snow-per-storm country and, for wind-abatement, we can tether it to the garden fence if need be.
At the last minute, we consulted our handy Polytunnel Handbook and opted to hold down our plastic on the sides by digging a trench and burying the plastic in that trench. For good measure, I added some gravel to the trench bottom to act a bit like a French drain. We like this trench method because, if you need to tighten the plastic, you can simply walk on the backfill a bit.
Here is the finished interion complete with gravel floor, small hoops for extra protection using row covers and lots of greens!
So we've gotten the old raised beds moved and transformed into a hoop house. What about that garden fence that needed moved so that we can restore our wetland behind the garden?
We did that too!
Back to the main point - we now have our easy, simple, cheap hoop house after all these years. Our advice to others with similar desires: go for it, keep it simple and have fun!