I stare at roofs too much

Did you know you're recommended to have R48 insulation in your attic in Chicago?
Signs your roof doesn't have enough:

• Icicles.
• No snow on your roof.

That translates into roughly 15" of rolled out fiberglass insulation (more interesting info here).

The very first project in the house was to add two layers of R30 insulation rolls in the attic.  We are overachievers who threw 20ish inches of insulation in (trust me: hauling 20 insulation rolls off the truck, through the yard, into the house and up two sets of stairs - more work than it sounds like).  Now we never get icicles on our roof.  But I can't stop looking at the roof to make sure we don't have a hotspot - and now I stare at everyone's roofs.  It's like a tick.  You walk down the sidewalk, you stare at roofs.

You stare enviously at all the houses covered in snow and simultaneously long for icicles, because they are quintessential signs of winter.

Here is my simple insulation breakdown:

You need to insulate your roof.  If nothing else because heat rises and you'll lose the most heat through your roof.  You can insulate two parts of your roof: the floor of the attic or the ceiling of your attic.

• An unfinished attic space: insulate the attic floor because it keeps the heat in your finished rooms.  
• Finished attic: insulate the ceiling between the drywall/plaster and the roof itself.

If you have a house with roof cuts, plaster walls might be as good as your insulation can get unless you re-roof the house with enough room for insulation.  Some day in the future you can look forward to a blow-by-blow of that project....hopefully in 20 years.

Where to buy insulation:  anywhere you find a deal.  Seriously, insulation isn't like plumbing fixtures - quality and brand name don't really matter.