The final major part of our cistern shed (besides the plastering, which we'll do next year) was the doors. I spent a few days this week making these massive things, consisting of a simple frame and a double layer of rigid foam insulation. Other than a small snafu (involving incorrect measurements, failure to do a test-fitting, and the frames being four inches taller than they needed to be), the process went smoothly.
Tyler and I hung the doors this weekend, and mercifully, they fit properly without too much fussing. All we have to do now is install weather stripping, and we'll be all set for winter!