This little house is made from old windows on all sides. You can prop them open in the summer or close them in the winter. The floor is flat rocks. One winter I had geranium plants and root cuttings from them and they were doing great until the propane tank ran out of propane. Lost them all. So, either build your little greenhouse close to an electrical outlet for a space heater or rig up a solar heating system to overwinter plants and don't forget to have water nearby. Learn from my mistakes. My little garden house is now filled with all my garden implements; tools, tiller, pots etc. It sits right behind my garden so it is handy. Jenny wrens also love to nest inside the boxes and pots that are stored inside. It's a way to recycle that is useful; a giant birdhouse.
PS - this doesn't really look as bad as it photographs. It actually looks pretty when you can see through all the windows and I guess when the crabapples are blooming and the garden is bountiful...
