UPDATE:  The attached EZ Generator Switch is what I want to install by the heater.

I want to have two new breakers added to my panel in order to split off two rooms. I recently noticed that our downstairs bedroom is on the same circuit as the kitchen which is right above us. And our downstairs den is on the same circuit as an upstairs bedroom which is also directly above it. I can’t use a space heater in either the downstairs den or bedroom without tripping the circuit. Is it possible to put the den and downstairs bedroom on different circuits? It looks like I have some open circuits. 

Also,  I need to have a switch installed so that I can run my heater from a portable generator. I just bought a generator and plan on running an extension cable into the room where the heater is. It’s a gas heater and I believe that it’s just a 120v. I don’t want to install a transfer panel at this time. 

This is an example of what my brother did in his house in Detroit. It has worked fine for him. I’d like to do the same thing.