Can someone advise me on how to find out where the heat is leaking out
of my home? My heat bills are almost twice what some neighbors claim.
$1800 for a 1500 sq ft, ranch house. There is 6"+ of insulation on
the ceiling and say 3" (whatever was standard in 1970)in the walls.
Several years ago, I reduced the heat loss a little bit by replacing the
leaky in-the-slab radiant heating system with perimeter baseboard radiators.

All of the windows have been replaced. I shotgunned the whole place
with vinyl, low-E units and have since replaced most of those with
Andersen units.

An interesting observation is that the heat use (cu feet of gas) didn't
increase during the recent Winter when I has home all day. New England
was fairly cold and I had the thermostat up to "normal" everyday. That
says to me that the loss is in the boiler, running a lot and being
inefficient.

Now, if I talk to my plumber, he says that boilers don't lose efficiency
with age. He'll happily put a new one in for $3K, but doesn't think it
will result in much less heat loss.

Siding contractors promise much improvement but won't put a number on
it. That's about $6K.

The gas company will do an infrared scan for $150 but I'll have to wait
'til Winter. And, the scan will show what we expect -- heat loss
everywhere.

So, is there some kind of professional, maybe an architect or
professional engineer, that can analyze the situation?