Greenhouse design - choosing plastic for northern climates

[Fishybass]

Wondering if anyone can help me choose my greenhouse plastic. I am an experienced indoor closet grower. With the advent of legal weed in MN, I decided to build a greenhouse outside to grow in, to add space and light… but the challenges of growing outdoors are a bit daunting.

My greenhouse is small, about 9’ x 16’ - quarter-round shape attached to the back of a building. I will have electric heat. I plan on growing through the early frosts of November and will shut down before hard freeze, but if I can keep it going through winter, great. Planning only a handful of adult plants, and handful of smaller seedlings as well as some other garden growing in there. My space isn’t optimal. It’s full sun about 7 hours a day most seasons, but buffering that, it gets dapped sun from neighbors trees. I will probably add my old 400watt HID for supplemental lighting. To maximize light and warmth and other issues I was thinking of a high-diffusion/high transmission sheet plastic with UV IR anti-condensation coatings but it’s pricey stuff. And I’m worried about overheating in summer, where it can get to 100-110F. Is it better to do that or go with basic 4yr. 6mil UV greenhouse plastic at a fraction of the cost. Also debating about doubling up the plastic in either case for insulation. I can’t afford polycarbonate. Any advice?

 

[Imzzaudae]

Go to your local boat shop. The shrink wrap they use for boats in the winter will make a great covering, It's not clear. It's not cheep but it's not see threw.
It's tough and won't fall apart. Electric heat is expensive. Create an insulated room inside the greenhouse that the lights will heat when closed up. But you can open up when the sun shines and warms the greenhouse. You can make roof vents that open when it's hot and close when cool. Lea Valley tools.
End gable fans. I used to have a 12x 24 orchid house. Grew world class show orchids for many years. Got rid of the orchids and now I grow pot lol.
Of course south facing is best in the north.

 

[Homesteader]

Farm plastic supply and get 4 year 6 mil uv protected plastic.
I'm on my fourth year and it's still holding strong. I also use it for covering lumber cause it is fairly strong

 

[Fishybass]

Go to your local boat shop. The shrink wrap they use for boats in the winter will make a great covering, It's not clear. It's not cheep but it's not see threw.
It's tough and won't fall apart. Electric heat is expensive. Create an insulated room inside the greenhouse that the lights will heat when closed up. But you can open up when the sun shines and warms the greenhouse. You can make roof vents that open when it's hot and close when cool. Lea Valley tools.
End gable fans. I used to have a 12x 24 orchid house. Grew world class show orchids for many years. Got rid of the orchids and now I grow pot lol.
Of course south facing is best in the north.

I don’t mind see-through since I’m legal and the greenhouse is pretty well hidden behind a fenced yard. The rest is right on… The boat shrink wrap idea is intriguing. I’ve seen others mention this on other sites, but I can’t find much info on this application like transmission, building/wrap methods. Any good references you can suggest?