Posted: 16/10/2012 at 13:03
I bought my first greenhouse in February this year. Its been fantastic. Obviously I've not even had a whole year using it, but a few things are already evident. Firstly (as posted above) go for the biggest option. I got an 8 x 12, which seemed huge when empty but is now jammed full. Secondly getting a flat base is critical. I cannot stress this enough! Thirdly auto opening vents are a life saver, especially if you are at work during the day or go away.
I built mine so that it was open to the earth, and have half staging and half beds for things like tomatoes and salads. I have no idea if this was a good move or not yet!
Good luck - I've loved every second of mine.