Joseph Sandy who lives just 45 minutes away from me let me know that he has just put up Free plans for his 350 square foot house. Here is what he says about it:
The Plan Set for the 350 sq. ft. Usonian inspired house is finished, and available for you to download. The project page is here.
The plan set is simple but should give you all of the information that you would need. It was produced using SketchUp. Next time I will move over to Revit as to produce a more complete plan set.
A small house inspired by Frank Lloyd Wright’s Usonian houses. The basic L shaped house makes the best of its small space. The layout is open while still providing plenty of space for the kitchen, full bathroom, closet, and desk. Go here to download the file