Some obvious heat leakers. Windows. One a windy day,
curtains still should not move. For that matter, no place
anywhere in the building should feel air motion when outside
wind blows.

Other less obvious leakers. In the 1970s, contractors would
routinely say that insulation on outside wall between floors
was unnecessary. Easy to identify that myth. Floors on
inside rooms are cold. Same applies to the space above
foundation; where 1st floor joist meet on the outside wall.
Sill plate on foundation - did they forget to put a fibrous
insulator between foundation and first wood? Drafts at the
top of a foundation on windy days identifies bad construction
(that is quite legal). 2" insulation inside walls is classic
pre 1980 thinking. It should be at least 3.5" inside all
exterior walls - including places where interior walls join to
exterior walls. Today, most contractors still will insist
insulation in corners is not necessary. Furnace - where does
cold outside air come from to burn in the furnace? Does it
use interior air?

Heat ducts - in the 1970s, it was routine to put the hottest
part of the house - hot air duct - directly on outside wall.
Sometimes with only a 1/2" of insulation. Again, contractors
even in the late 1970s said this was good and acceptable.
Therefore the hottest part of the house is insulated to the
outside. Air ducts in attic spaces - must be beneath attic
insulation. And yet contractors in the year 2000 will still
claim tiny insulation around an attic heat duct is sufficient.
Attic access hole - is there insulation over the top of that
doorway or access hole? Foundation - any foundation wall
exposed inside the house that is within three feet below
outside grade must be insulated. Just a few ideas and the
many myth promoted by contractors then and today.

Stubby wrote:
My heat bills are about twice what neighbors pay in similar houses.
And, I get ice dams. So it seems there is heat leaking up into the
attic. I have soffit vents and a ridge vent. So I called 3 insulation
contractors. One said the 6" that is in the attic between the 2x4
joists is fine and that adding more won't make a big difference. Two
others wanted to add another 6" of cellulose. Pink stuff is more
expensive and doesn't fill nooks and crannies as well.

My walls have 2" insulation which was standard back in 1970 when the
house was built. I replaced all the windows with double pane vinyl
windows. That was years ago and it did make a difference. I have a
large aluminum frame slider that I cover with film for insulation.

I'm hesitant to spend $1600 on additional insulation if it isn't going
to do anything. Can anyone suggest what is causing the heat loss?
Thanks.