If you do a propane furnace go to a 94% efficient and side vent it, you don't need a chimminey anymore, and if you get a Energy Inspection (about 150 bucks)the Cdn gov't will cough up anywhere from 500 to 1700 in rebates,(You are in Canada, right?) All you reinsulation could have gone under this program as well same as energy efficient hot water tanks, windows doors, etc.