Build a root cellar - PEM BB building.wood.rootcellar

This is a badge bit (BB) that is part of the PEM curriculum.  Completing this BB is part of getting the wood badge in Building.

While building a house may be out of reach at the moment, let's get some practice putting together medium sized structures. Foundations and earth work can be a challenge.  Maybe you can get some practice on a building that would benefit from being a little damp.  Let's build a root cellar!

Here are some pictures of what we're after:  
 
 

And here's a photo montage of a build.  Maybe a bit less concrete is in order:


Minimum requirements:
  - At least 80 square feet (interior)
  - At least 6' interior headroom
  - Earth sheltered/bermed on three sides at least 80%
  - Floor isn't concrete
  - Air inlet (low) and outlet (high)
  - No:
        - Pressure treated wood
        - Railroad ties
        - Septic tanks, big culverts, tanks or other prefabricated structures
  - As with all PEM badges, lesser BBs can be harvested as you complete this project

Provide proof of the following as pictures or video (<2 min):
  - Place where the root cellar will be built
  - Excavation complete
  - Foundation complete
  - Walls complete showing at least 80 sq ft
  - Roof complete
  - Air inlet and outlet
  - Completed root cellar