Pulling permits in Philadelphia? Need Advice - First-Time BRRRR

[Sharma Parth]

Hi guys - we are about to close on a property soon in Philly and are planning to do the following work - 

-Add HVAC, Add a full bathroom and add a half bathroom, Fix kitchen (keep same layout)

My contractor is saying that (Approach - 1 ) - we don't need to pull permits. We can finish the work in 8 weeks. After that, I can request a CO from the town and then make it easy for me to rent or sell it. (Approach - 2) - He says that if he is asked to pull permits, he is not responsible for any additional work that the inspector may throw (basically more money out of my pocket on the rehab costs). In his experience, for this job he says we don't need a permit and it will only cause more delays. 

We are torn between both approaches here.

Cam someone suggest what approach is better? If we don't get a permit then does the inspector for the CO ask for it when he/she comes for inspection? or they just care about the house being "liveable"? 

Thank you in advance!