Renting a house with un-permitted work in the detached garage

[Piper Prost]

We are planning to rent out a SFR, and it comes with a detached garage.

A few years ago, there was un-permitted drywall work to finish the garage, and a window and door were added. We have not used it as anything but a garage for storage.

Now we are planning to rent the HOUSE out. Any and all work in the house is up to code and permitted.

How do I make sure everything is legal with the renters as it pertains to the garage? Should we put in a clause in the contract that the garage is not included to minimize my risk? 

I have a renter interested and she is a fitness instructor. I think she wants to use the garage as a gym.... it is a nice garage and a selling point, but I want to minimize my risk. 

I am in Los Angeles County.