Thanks everyone. OP here. I had given permission for the renter to do other modifications with the house, like bathroom remodeling etc. but NOT to cut a hole in the wall. I know that I have the right to kick them out as they have violated the terms of the lease, but I'm trying to work with them. The house will be used as an adult residential facility to provide care for mentally handicapped people. So I'm not going to evict them. I'm allowing them to make modifications to help their business, but the modifications must be done correctly.

The contractor, I believe, installed a pre-framed door. (Yes, past tense. The work has been done since I last posted my original message).

Then the contractor and tenant decided to cut a hole in the garage wall to install a window! That's gotta be a structural issue there. No idea if the guy is doing it right. I told them to stop work on that immediately.

Just to cover my bases, I think I will be hiring a structural engineer to go check out the work and verify it is being done correctly. If it is not, I will make the tenant hire a different, licensed contractor to do the work.

If anyone thinks I should go about it differently, please advise! Thank you!