Options for insulating the walls of an existing home?

[randr]

4. There are many variables to insulating, especially an older home

First is where you live as the insulating values are dependent on ambient temperature differences.
The amount of glass/windows and their insulating values must be considered.
In most US climates windows and walls can share an equal value in heat loss, depending on many particulars of course.
An analysis of costs for both systems must be looked at.
I live in a high desert region of Colorado where winter heating is almost equal to summer cooling when insulation is considered.
Many older homes I have seen brought up to modern specifications have had all windows and doors replaced, a new exterior consisting of stucco over a layer of high density styrofoam, and a blow in type of insulation in existing wall cavities.
Research all three of these options and choose the one that fits your budget and gives you some satisfaction.
You may find local sources of information if you have an Energy Resource Office nearby.
Check out this later post: http://www.democraticunderground.com/115847