We burn wood in our wood stove, that's our main source of heat.
We have a gas furnace and the first winter before we put in new windows and the wood stove my gas bills were $300 a month!
But since the new windows and wood stove our monthly gas bills are around $40.

The temp in the house is always around 70. It's nice to sit and watch TV in shorts and a t-shirt all year around! But the dogs don't like it!