Unless your home was specially constructed for energy efficiency, you can probably reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but even adding insulation to a newer home can pay for itself within a few years.
To determine whether you should add insulation, you first need to find out how much insulation you already have in your home and where it is. A qualified home energy auditor will include an insulation check as a routine part of a whole-house energy assessment. An energy assessment, also known as a home energy audit, will also help identify areas of your home that are in need of air sealing. (Before you insulate, you should make sure that your home is properly air sealed.)
If you don't want an energy assessment, you need to find out the following for yourself:
If you live in a newer house, you can probably get this information from the builder. If you live in an older house, you'll have to inspect the insulation.
*Thickness must not be used as the sole factor in determining the R-value of loose-fill insulation, particularly for attic insulation.