I'm trying to use Cell Fracture addon to 'break' simple building model but it causes additional geometry which makes model very ugly. Original model:
After Cell Fracture:
I understand it is something wrong with my model because other models I tried works well. But what exactly wrong with it? I applyed location, rotation and scale but it not helps at all. I also tried to triangulate the model (previously it helped me to resolve UV unwrapping issues) but it also not helps. The .blend file is uploaded here. Thanks in advance.