I had a carpenter come give me an estimate on repairing a fascia damaged in our last ice storm and asked him if he could build a greenhouse for me. He has built one before covered with film but not poly. I want a twinwall polycarbonate. So a few questions:

1. Anyone got a good plan for simple but sturdy 8 x 12 wood greenhouse? Or another size under 100 sq ft floor space. Or a recommended source for plans...
2. And what is best source for polycarbonate panels (quality and reasonable prices).
3. Would your preference be to go to the ground with poly or build up with wood a foot or so (not sure what that term would be). I'm thinking that might be cost effective to cut down the cost for the panels, since they seem to be pricey. I do plan on growing in ground though, so is that a bad idea?
5. I was wondering if I should just insulate north wall, but that faces the house, and not sure how good that would look...thoughts on that?
6. So if you're building one from scratch what tips and tricks would you suggest?

I looked into building a GH with polycarbonate panels before I decided on film instead. The panels being the majority of the expense, I was laying out the size based on the length of panels/ least waste possible.

So long story short you don't want a 7' side wall that you waste 1' of panel from every one. I believe I was planning to use sheet metal from the ground to only need half of a poly panel for each (4' wide) wall section.


I think I found what I considered decent prices on the poly panels at a local Menards. The online prices were just too much with shipping.

1. There are a gazillion free greenhouse plans on the internet. Pick out one that you like and fits your needs.

2. Take a look at Greenhouse Megastore. They are going to be expensive no matter where you buy them...the most expensive part of your greenhouse.

3. It's called a knee wall, and it will cut down on you poly cost. If your greenhouse is positioned properly, it shouldn't affect your plantings.

5. I insulated my north and east walls. Most of the sun you want is going to come from the south and west. To make them poly is another waste of money.

6. a. Insulate under the greenhouse or create a Swedish Skirt around the greenhouse.
b. a door at each end for extra summer ventilation
c. automatic roof vents
d. handy supply of water
e. run electricity to the gh

As far as good pricing on glazing. Where abouts do you live? I just bought six, 6 x 8 foot sections. i am building a 8 x 12 foot green-house right now. Spent this afternoon on the south wall, and some of the framing.

I applaud Jim's post (Moonshadows). A thoughtful outline for a well done greenhouse. Brilliant. Too often people just build and then go oops! when it gets hot or cold.
Bruce

Highcold: I am in the Oklahoma City area. Someone on FB recommended Menards, we don't have those here. There is one in Wichita however, which is only a couple hour drive. So could save on shipping cost by picking up there. The shipping costs on these panels from the greenhouse stores is astronomical!

BruceM2 said:I applaud Jim's post (Moonshadows). A thoughtful outline for a well done greenhouse. Brilliant. Too often people just build and then go oops! when it gets hot or cold.
Bruce

LOL. I was one of those people! Most of the suggestions I made in that post are a result of learning from my mistakes. I've done a lot of retrofitting since I first built my greenhouse in 2016.