Permitting - Thinking about buying unpermitted houses

[Troy Takamoto]

Hi BP,

I'm new to the bigger pockets forums.  I found a lender sale with 4 single family homes and 1 duplex.  Just did the walk-thru and the homes are about 90% complete.  After the walk-thru, I found out that all the single family homes were built unpermitted.   The unpermitted houses are above ground and has an attic so easy access to check wiring and plumbing.  

Does anyone have experience with getting the permits and home inspection after the fact?   How much it would cost?  What steps do I need to take?  

Any advice would be greatly appreciated.  Thank you.