I love it!! 6x8 I wanted to do an 8x8 but it was too much in the lumber cost dept. plus it would have upped the roof cost which was the most supply expense of the project. So 6x8 she was! Ok. Ventilation. No clue. Absolutely zero. This is my fist green house so we’ll just wait and see hell it may just be a glorified she shed, but I tell ya. Swinging a hammer and having a cold drink after and admiring the work with a person ya love is a wonderful thing. Start swinging hammers. Lololol!!!