For most homeowners in the US, the biggest expense is heating and cooling. If you don’t have adequate insulation in your home, this will increase the cost, sometimes significantly.
When deciding on what insulation to install in your home, you want to determine what R-value it should have. R-value is what measures a material’s thermal resistance when properly installed. If improperly installed however, it could be a lot less effective than its R-value indicates.
Insulation should never be compressed, because this will lower its effectiveness. It also will not mitigate air leaks resulting from structural defects in your home. This means that even though a wall is insulated with insulation of a certain R-value, the value of the wall in its entirety could be lower.
An assessment of the insulation could be done using a simple device called an infrared thermometer that shows the temperature of different areas of your home. This will show you where there might be poor insulation or a leak.