Great job, one thing to point out is that no matter how well engineered your insulation job is, letting 'small things' go can severely undermine your efficiency. Specifically, I'm thinking about keeping your air filters clear and the fact that one door with poor weatherstripping is similar to poking a rather large hole (a few sq cm) right through your painstakingly developed wall.

Kudos on making your own illustration. If I might suggest one thing, explicitly mention that it's in the public domain or released under a CC license (if that's your intent). In some jurisdictions, public domain can't be assumed and I think it helps google's image search engine identify the work too.