I saw a really cute and functional greenhouse for sale at a tool outlet store in the U.S. called Harbor Freight. I don't know how broadly their stores are distributed, but I found a nice little model of it yesterday when I was looking for some storage bins. This structure is a bit too small (not tall or wide enough) but it is along the right lines. A friend of mine has a big plastic one they bought at Sam's Club many years ago and it is really quite durable and well designed. It looks very elegant out in their back yard.

SRS