That sounds like an excellent idea to me. I have one layer on the roof and one layer on the ceiling, leaving six inches of dead air space in between. I didn't do the walls, as they are double paned windows and look lovely.

For economical heat, the folks on this forum recommended an oil filled radiator, and I have to say, it was an EXCELLENT choice. Not only are they affordable, but they work very well and are efficent to use. I put a link below to amazon so you can see what they look like and read customer reviews of the product.

Here is a link that might be useful: oil filled radiator

Thank you for replying to my post. I received the Magni-Clear yesterday and noticed that the air bubbles do not seem to be full of air like the bubble wrap stuff. Is this normal?

If you press the 'bubbles' between your fingers, you will see that there is some air in them I'm sure. Maybe they don't fill them real full to allow for expansion in the heat. But the bubbles will definately help with the insulation and as you can see, the plastic is really sturdy.