Just wanted to post this for anyone who is looking for a smaller patio-sized greenhouse. It is 38.6 inches wide, 22.8 inches deep, and 73.6 inches tall at its pinnacle (so, about 3 feet wide, 2 feet deep, and 6 feet tall at its peak). It is sold through a number of places, and best price we found was around $250 with free shipping; ours was purchased through
http://www.minigreenhousekits....
Two of us assembled it in about 3 hours with no difficulty from the instructions (pictures and text) and needed only screwdrivers to complete. Though most sites selling this product mention that it is either silver or green aluminum, and show sliding versus swing-out doors, our unit came in silver with swing-out doors. The only hitch was one of the doors had hanging-pins that were mis-manufactured (pins were "upside down" to what they needed to be), but customer care for this site was superb. They immediately shipped out the correct replacement part, with tracking number, and the new part completed assembly of the entire unit in under 10 minutes.
Though it is listed as 35 pounds, the box felt much heavier to lift upon arrival, requiring both my husband's and my full joint effort to move. In fact, we ended up just taking pieces out to the porch in easier-to-haul batches. I am glad for the heaviness, as we do get high winds in the winter, and the unit is stable on its own - even more so with potted plants inside of it.
I'm using it to start daylily seedlings, and I have had it filled with small pots of them for over a month now. It also houses some mature daylilies that need nursing through the winter, and a few tender fuchsias. They all are doing amazingly well, and far better than seedlings at a comparable stage of development last winter. During the summer the outdoor thermometer in the greenhouse reads a consistent 10 degrees warmer than the outside temps , and this is keeping them in the high-60-degree range rather than exposing them to 50's overnight. I anticipate that this small greenhouse will be able to get the seedlings well through our 9b winter (a few weeks of below-freezing overnight temps) without me needing to worry or fuss with covering and tending to them other than normal watering/feeding needs.
Certainly, it is a greenhouse for someone starting out, or just needing something smaller, but it does fit great in a small space, looks very pleasing to our eyes (like a true "mini" greenhouse), and holds quite a lot of plants for its size.
Update Winter 2013/2014: I was worried about how much warmth this small greenhouse could really provide once the temps went below freezing, but am pleased to say that it consistently keeps its interior 20-degrees warmer than the coldest outside winter temps! I did add a rubber weather-strip on the back of the doors, as our assembly left their closure a little "off" with a small opening letting the wind in where the doors join together, but that one fix made all the difference. Now when it is 27-degrees at night the inside stays a nice 48-degrees without any type of heat source. Just what I needed!