I have seen the video of the buy with the green face should i just follow his instructions and build it like his?
Fuck no...I don't know where that green monkey is from, but that is not the way to do it in Colorado.
Don't lessen your space by building unnecessary walls and ceilings. Work with what you have. Learn to maintain furnace and water heater yourself. Basic home maintanence is a very valuable skill to develop.
Look for low profile windows that can be used for exhaust/intake. You don't want to be exhausting street side, right?
Figure out how much space you want to dedicate to the grow.
Remember,(if rooms are in circuit) veg room first then flower room. Vice versa and you will be cussing.
When you post pictures, you may want to start a new thread to get better assesment.
Edit: Yeah that guy is a fool, I don't listen to what he has to say. 1st off, you don't want them side by side if you have the room to put them at opposite ends for two reasons; bugs and other crap will be distanced that much more from your two rooms, and it will leave you room to expand the flower, should you decide to. It will not stress the plant anymore to go 2 ft or 20ft for transplanting.