I've got a ranch house with an attached garage. The garage is not in any way insulated which doesn't really bother me. What does bother me is there is no wall in the attic between the house and garage. I live in upstate NY and the winters are pretty cold up here, should I build an insulating wall between the house and garage?

Is there not insulation in the attic ( home ceiling) and is not the attic vented anyway,?

Personally I would insulate my garage

I've got a ranch house with an attached garage. The garage is not in any way insulated which doesn't really bother me. What does bother me is there is no wall in the attic between the house and garage. I live in upstate NY and the winters are pretty cold up here, should I build an insulating wall between the house and garage?
I would love to insulate my garage but really cannot afford it right now. I was just looking for a short term (1-2 yr) quick fix to conserve any heat lost through the attic which is insulated and vented at each end of the house.

So you have vents on each end of the attic, so you can't be losing any more heat than just having it open. It is the attic insulation that is so important,

Yes I Would Build A Gable Wall Between The Too But You'll Still Need Access To The Garage Ceiling For Code And Or Access To Wires
After You've Built The Wall Insulate With R13 Or 15

We just added an attached garage and the wall between the garage and the house had to be completely sealed by code... insulated and sheetrocked and crack-filled the gable wall goes straight up and completely separates the garage from the house.We definitely wanted this done also because of the risks of asphyxiation from car fumes.

COACH78 , no, don't build a wall. And no one here has mentioned the fact that with the venting of the attic being on both ends, you can not build a wall between the garage and house because you need the ventilation to give a longer life to your shingles. And to let the house "breathe". If anything, add more insulation to the attic section of the house.

Okfirst of all! The access to the garage needs to be in the garage ceiling,either a drop down stairs or just a small access. The access need to be firerated, The wall up in the attic needs to be framed up and insulated compeletly, however I mentioned an access in the wall which is fine but you do need to have a access door there , that is solid core and has weather striping on it, that's my fault for not getting into more detail.
As for ventalation, most likely you will already have a gable vent as it is right now, you probably have ridge vents and sofet vents, this is pleantly of ventilation for the garage,
You don't not have to have venting on both sides.

So I guess its OK for them to die from car fumes as long as the roof can breathe.

Any attached garage for the purpose of storing a vehicle needs to be completely separated from the living portion of the dwelling with a solid barrier of 1-2 hour fire rated material. This may be as simple as one layer of 5/8" fire rated sheetrock. This is to prevent or slow down the spread of fire that begins in the garage to the livable portion of the dwelling.

If building this separation would block the one end of venting the attic needs, additional methods of venting will need to be added to vent the attic properly. This can be eave venting, roof penetration vents, or a peak vent.

A certain amount of square inch of venting is needed for a certain amount of square foot area of attic. Best to check with your local building code enforcement to learn what code they enforce.