If you are talking about the LJR sheds, it's because the configuration names are wrong in the xml files. The names in the placeable xml should match the names in the modDesc.
For example, if a configuration is named "outerWalls" in modDesc, the keys in the placeable would be <outerWallsConfigurations>, <outerWallsConfiguration>, etc. That's the vanilla naming, adding Configurations and Configuration respectively to the end of the configuration name. From there it follows the Giants vanilla configuration scheme.
If I can get ahold of LJR, I'll let him know.