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
