Greetings,

I live in a VERY old house in New England and the windows look like
they could easily be 40, 50 years old. Obviously replacing the
windows with better models would be sane but that isn't an option at
the moment.

I'm taking it for granted that the plastic film-type window insulating
kits are worth installing but I'm trying to figure out *how*
worthwhile they are in terms of cost savings. Obviously nobody can
give me a precise dollar amount without a detailed analysis of the
windows, the temps, the heating elements and floorplan ...but are we
talking a marginal savings, moderate or downright huge? 3% less oil
consumed? 5%? 10% or more?

Thanks much in advance,
Jason