If you live in an area where you need a permit to build a garage and you do not get the permit to build the garage then eventually the city code enforcement or town code enforcement will come around and issue you a citation if you have a newly built garage and you didn't pull the permit.
I hate having to get permission from someone to build things on my own property but if you live out in the city or town and they require permits to build things such as the garage then you must get the permit.
If you build the garage without getting a permit first then the city or town can fine you which can be a lot more than the cost of the building permit.
They can also make you tear down the garage even after they fine you.
Getting a permit is pretty easy and not all that expensive.
If you live out in the countryside though like I do now then you can build something without needing permission.
I used to live in town before and hated it and now I made the best decision to sell my in town house and property and move out to where I have no neighbors.
I had a new house built here and they didn't even pull permits although a lot of them would.