I finally got around to building and installing the East doors. I came up with a better locking system for the doors. I'm using a gate latch with a cable through the door so you can unlock it from the inside. I made sure that the the plastic covering I was using to cover the doors completely covered the hinges as well. This insulates the greenhouse much better than having gaps. The temperature outside was about 45 degrees and as you can see from the thermometer it's about 75 inside the greenhouse. I checked it this morning and the ambient temperature was about 40 outside the greenhouse and about 45 inside the greenhouse. I am definitely going to need some sort of heating system to make this work.