I have a 50+ yr old tri-levelOur gas bill was outrageous last winter and I am trying to fix itI already bought a timer on the thermostat so I can turn the temp down while at workToday I bought a couple of cans of foam insulation to spray in vents and electrical areasI have new windows so that is not the problemAny other ideas?
Better (stronger, thicker) floorboards in the attic would be a start, and decent insulationYou would need to build the space between the first floor and the attic as you did the space between the ground and first floorsFor more money you can invest in soundproofing of the floors, or even use pauper's soundproofing - egg boxes filling the space under the floorboards will soak up most noise!
the attic is the greatest source of heat lossheat rises and if you can not trap that heat through the ceiling your bill will be outragiousThe new windows will help and if you insulating your walls it make the place more comfortable but do very little to reduce your gas billblown in insulation is probally the cheapest method to insulate your attic and it is very effective.
Don't forget all necessary HVAC runs and electrical such as outlets, over head fixtures, cable and phoneIs the floor strong enough to support this? If you have typical roof trusses, that won't be sufficientGood luck with your project.
