The air ducts not fitting together well

My sister and I decided to let me move into her home with her.  I was amazed at how different we are when it comes to what we want with temperature settings.  It seems that just as soon as I begin to get warm, she is complaining how hot she is and she wants to turn the thermostat down.  I’ll be living with my sister for the next four years, until I finish my schooling. I don’t want to have to be constantly fighting with over the thermostat.  I know that my sister isn’t very happy with me, because this is her home. I can’t just stop being cold, and I don’t know what to do. I thought about going out and finding my own apartment, but when we talked the problem out, we came up with a completely different solution.  I was being to wonder if maybe we couldn’t have Zone Control installed in the condo. I offered to pay half for the Zone Control, and there we would each have our own thermostat in our rooms. My sister wasn’t sure if this was the step she was willing to take, but I assured that I had talked to the HVAC company and they said it wouldn’t involve any kind of intrusive procedures.  They simply put small valves into the HVAC ductwork, and make it so that the air can be separated and sent into different areas. It is better than closing the air vents, and it is better for the energy bill. I then have the choice to not use the furnace. I know she is considering putting Zone Control into the entire condo now, but I don’t think I want to have to pay half of the bill if she is putting it all over.  

HVAC zone control