Building extra room in attached garage.

We are seeking to break through a service porch back wall to build an extra room in our attached garage. It would be done by a licensed contractor but unpermitted and would be removed in the future. The size would be about 11x13. good idea or terrible idea?

Fire and electric code issues need to be met, particularly being that it is attached to a residence.

I wouldn't think of doing this without a permit and inspection. If done wrong, the house could have it's occupancy denied and you would be looking for place to stay until it is brought up to code.

There are strict requirements for a bedroom, as far as access, AND emergency egress, which your contractor should know about, but I cannot imagine any licensed contractor being willing to assume the potential liability by NOT getting it permitted. I also assume this will FILL the garage so you cannot park a car in the garage.