Try posting to the original thread.....you may get answers.

I haven't really been back to Gardenweb in several years but just popped in on a whim and saw your post!

That greenhouse is now 12 years old and still being used. We did a fairly major renovation to it this spring as the old windows in it were 50-100 years old when we built it and were starting to rot and leak.

The GH is 16' long so you can figure from that the rough size of the windows. But you can just design your own greenhouse around whatever size windows you are able to find!

We removed the old french door windows from the roof and just built an asphalt shingled roof with two skylights I bought used. The front wall of windows were also replaced by used windows...I lucked out on some matching, quality brand, vinyl windows at a salvage store!

The GH is supported by concrete piers poured into Sonex Tubes in the ground. There is a pressure treated sill on top of those and the framework is pressure treated 2x6's with insulation in the walls.
The paver brick floor is just on the ground, on a bed of sand.

You will find that keeping the GH cool is just as important as providing heat. In spite of being able to open doors and windows and having an automatic venting window in the ridgeline of the roof, I still couldn't count on the GH not overheating...especially if I was at work all day and not able to control everything when it needed to be. So we installed an exhaust fan on a thermostat and then things were perfect! So with that knowledge now, I would have just installed one at the beginning and saved myself a lot of aggravation!

Here is a recent photo of the greenhouse after it's renovations. There is not as much glass as there once was but still plenty enough for starting and growing on plants. I don't plan to heat it all winter anymore...maybe just in late spring as I moved seedlings out there. I moved my 3 tiered light table to my heated, bright basement and can start seeds there as early as I want.

I painted antique screen doors and a cupola that we found at different salvage shops and added them too, during the renovation.

Taken last week when we had about 8" of snow...it's all gone now!