Have you looked into taking the metal roof and sides off and replace it with either the pollycarb or the clear fiberglass roofing. The framing looks good. As far as putting tools in the growing area, I think it would be a bad idea as you are going to have excessive moisture for tools.
The sides could also be screened in and in the winter when a freeze is comming you could have .06mm clear sheet polly film on rolls at the soffit.
I saw a nursery in Branford with the cheap panels (clear, sort of) on a roof that is similar to your metal roof, with screening on the sides. They tell me that they cover the sides with plastic film and they never had to heat it. I am going to build something like that.

I have a friend in Newberry that has a 2000 sq ft greenhouse built with pressure treated wood and the roof is permanent...its clear fiberglass, but the walls are all screen. In spring, summer and fall they just leave it open, in late October they wrap it with 6 mil Viscreen and that stays on through the winter. Works for them but they DO heat on nights when a freeze is forecast.

thanks for the responses. I plan on taking the roof off and using 6mm or 8mm clear poly carbonate. what do you reccomend for my climate and needs? the greenhouse is on the southeast side of my house.

I plan to leave the right half of the greenhouse a toolshed/workshop/ (the "A" fram roof) the left half that currently acts like a carport will have the polycarbonate roof. I want to find one or 2 sliding glass door for the front these will be the entrance.

as far as the rear wall and left wall are concerned, you guys suggest I screen these in and use plastic sheeting as a "roll down" type curtain in colder winter months?

The green house will be used for growing palms in the winter. It will also have a seed starting incubator table for cactus and other seeds. I also will grow cycads and aloes.

Doing poly carbonate on the sides and rear would be a waste of money? These to areas but up agaist a fence and dont allow much light in.

Would exhuast fan be needed, or would the screened siding allow for enough ventilation.

thanks!
Luke

I have a basic layout drawn in mspaint. feel free to give me ideas. save the picture and edit if you'd like. (i'm very visual){{gwi:300526}}
thanks
Luke