I just moved into a house and am a little bit disappointed in its thermal performance so far. It's winter and cold outside, and the furnace heats the house up pretty quickly, but then the house gets cold again pretty soon. So the furnace is on, then off again, then on again, and I suspect it's not reaching its efficiency potential from this. Furthermore, the dry air blown around the house isn't terribly comfortable in the already-dry northern New Mexico climate. The tile floors set right on top of the slab are really cold. The gas bill is irritatingly high.
So I'm wondering what I should tackle first to to remedy this situation. Here are some more details:
- The house is a 42 year old ranch-style, and the conditioned space is 1,200 square feet.
- The house faces west, so the main living area only gets direct sunlight early in the morning and in the late afternoon.
- The heater is an 80% efficiency 125,00 BTU central forced air furnace with ducts in the unconditioned attic and vents in the ceilings.
- There are lots of air leaks.
- There is a large sliding glass door that was double-paned, but one pane is missing
- The entry door is un-insulated.
- The walls are 2x4 construction with fiberglass insulation.
- External sheathing is cream-colored stucco, with no continuous foam insulation or anything nice like that.
- The attic has loose cellulose insulation, about 6" maybe. Higher in some places, lower in others.
- The roof sheathing is made up of light red asphalt shingles. Roof decking is 2x10s.
- The house is built on a slab-on-grade which is not insulated at all. The footings have been extended outwards to form a ring of concrete around the whole house that you can walk on, making it impossible to effectively insulate the edges without removing the extra concrete first.
- The windows are double-pane, but old and aluminum-framed. The aluminum frames feel very cold to the touch when it's cold outside. They also do a terrible job of noise cancellation. Inside the house, you can hear people 30 feet away outside.
- There is an attached, uninsulated garage.
What should I do first? I'm planning to stay in this house a while so I'll have time to tackle large projects eventually (i.e. replace shingles with metal roof, add continuous foam insulation) but I'd like to know what's the general order I should tackle things.