Hi Thomas,
Yes, you can perform room-by-room calculations. If you are performing a load calculation on an existing home, each trace you make in step 1 creates a room in step 2. My preference is to treat each floor of the home as a room. If you would like to do a true room-by-room calculation you should skip the tracing features on step 1 and proceed directly to step 2. The only downside is you will need to enter the dimensions of each room manually.
Once you are on step 2 expand the system 1 > zone 1 section headers and create your first room. Once your first room is completed you can create additional rooms by clicking the + button on the room section header.
I hope this helps
Bill