Permit for bonus room

[Eric Gadus]

I am looking to finish a room above a garage on my first rental. Flooring, drywall, insulation, electric, and HVAC will be needed. I am not making it a bedroom, just an extra room for an office or whatever the renter uses it for. The contractor says all items will be up to code. However the city the house is in, Birmingham, has a lengthy permit process, and the contractor says he has no interest in getting a permit. Should I be worried about this? He insists since I am not making it a bedroom I do not have to worry about egress. Sidenote the renter is paying half of the cost, to good not to pass up. Thanks!