While every house is different, the basic rule of insulating is the same for all homes: install insulation on any surface separating a heated space from an unheated space.
Adding insulation to your home can cut heating and cooling costs by 15% or more, depending on factors such as the amount of existing insulation in your home, house size, air leaks, personal energy use, and living habitats. Even if your home already has some insulation in these areas, there can be great benefits to adding more, especially in the attic.
In the attic
The attic is one of the easiest places for insulating do-it-your-selfers to start, as it offers easy access relative to other areas of your home. You can install loose-fill, batt, or blanket insulation over any existing insulation. If you choose to use a blow-in or spray-on insulation, you will want to have it professionally installed. Special architectural features like open ceilings, flat roofs, and the story-and-a-half will also usually require professional guidance.
A professional energy assessment will help you find out how your current insulation is performing. Insulation is rated by its R-value, a term that indicates the material’s ability to resist temperature change. You can find the R-value on an insulation’s packaging (for example, “R-13”). A higher R-value indicates better insulation performance per inch.
To estimate the total R-value yourself, simply multiply the insulation’s labelled R-value by the total vertical height of the insulation in inches. [EXAMPLE]
Here in Minnesota, you should aim to insulate your attic to R-50.
Around the home
An energy assessment will identify many of your specific problems and areas of improvement.
Be sure your walls are insulated, and insulated property. Most homes built before 1960 do not have insulated walls or are insulated by products not up to modern-day standards. In basements, attaching wooden studs to the foundation wall and installing fiberglass insulation is no longer recommended because of its potential for mold and mildew. The most appropriate solutions now are complex and generally require the assistance of an experienced contractor.
An uninsulated basement means a lot of lost energy. Insulate foundation.
Insulate floor over unheated spaces like garages, crawlspaces, and bay or bow windows.
Insulation always needs a vapor retarder.