Why does my home need insulation?
Heat flows naturally from warm places into colder places. This means that all winter long, as your furnace is pumping out heated air to warm your home, that heat is trying to escape outside, or into an unheated garage, attic or basement. Conversely, in the summer, when your air conditioner is working hard to cool the house down, hot air is pushing its way indoors. In fact, the cooler the indoor temperature, the faster the heat wants to come in. So whatever the season, home insulation is needed protection for your home. It provides a barrier to heat loss and heat gain, which means you'll use less energy running your heating and/or cooling system, and ultimately spend less on your utility bills. If you live in a newer home, chances are your insulation is sufficient for your regional requirements; check with the builder if you want to confirm the specifications. But if you have a home that was built more than 30 years ago, or you have any additions, you might have inconsistent or insufficient insulation in place. It's time to check and find out!

How much insulation does my home need?
The amount of insulation required depends primarily on the region you live in - colder winters generally mean a higher level of insulation is needed. The DOE has published a guide that shows, zone by zone, how much insulation your home requires.

What does R-value mean?
In the DOE insulation guide, the amount of insulation required is designated by an R-value, which is simply a measure of thermal resistance. The higher the R-value, the more effective the insulation will be. An inch of wood has an R-value of 1, which means it is not very effective at keeping heat from passing through. Concrete and brick is even lower. You can improve the R-value for buildings made from these materials by adding insulation. The R-value will be prominently featured on any insulating product that you purchase. The Federal Trade Commission has strict guidelines about labeling on insulation. Make sure you read the label thoroughly to ensure it matches your needs, and that you are aware of any special usage considerations. R-values are determined by the materials the insulation is made from (such as fiberglass, cellulose, polyicynene and polystyrene), how thick the layer of insulation is, and how dense the material is. You can increase the overall R-value with a multi-layered installation, for example combining blanket insulation with loose-fill. Just be sure to put the lower density product on top, because compressed insulation will not give its full-rated R-value.

What types of insulation are there?
There are many types of insulation available, depending on your specific needs and budget. This chart defines the most common types, what they look like and where they are best used.

Type of Insulation	Blanket	Loose Fill	Foam	Rigid	Radiant Barrier
What It Looks Like	​Comes in rolls or batts in standard widths to fit between wall studs and attic floor joists.	​Blown-in loose fibers or fiber pellets.	​Spray-on foam.	​Board-like forms and molded pipe coverings, often faced with reflective foil.	​Aluminum foil with paper, cardboard or plastic backing.
Materials	​Fiberglass or cellulose (plant fiber). May have paper or aluminum foil facing.	​Fiberglass or cellulose (plant fiber, recycled paper fiber).	​Latex or polyurethane.	​Polystyrene or polyurethane.	​Aluminum foil.
R-Value	13 to 30	30 to 50	6.5 to 12.5	3.8 to 6.5	N/A
Usage	Walls, floors, ceilings. Great for DIY. Must cut to fit around pipes, wires, and outlets.	Wall cavities. Unfinished attic floors. Irregularly shaped areas and filling in around obstructions.	Good for sealing around windows, pipes and other small openings. Larger application requires professional installation.	​Foundations. Wall sheathing. Excellent at reducing heat conduction through wood and steel studs.	​Most effective in reducing downward heat flow. Keeps home cooler in hot, sunny climates.

How can I find out if I need more insulation?
Indicators that you need additional insulation include:

• Drafts in your living spaces
• Uneven temperatures between rooms
• High heating and/or cooling bills
• Cold floors in the winter
• Pests (insects or rodents)
• Dust smells from an attic or crawlspace

Do I need to hire someone to install insulation, or can I do it myself?
Depending on the location and the type of insulation, it's quite possible to install insulation on your own. Installing blankets, batts and rolls are an easy DIY project, and machines for loose-fill insulation can be rented in many areas. Large-scale spray-on foam applications need to be installed by professions.

Should I dispose of old insulation?
If existing insulation is compressed, water stained, or moldy, it should be disposed. Keep an eye out for lightweight, loose-looking insulation with shiny flecks; if it was installed before 1990, it might have asbestos in it. Get it tested, and hire a professional to remove it. If the existing insulation is in good condition, but there's just not enough of it, you can simply add more on top of it.

Should I insulate my garage or basement?
If you intend to use your garage or basement as additional living space (for example, if you want to use your garage as workshop) and you plan to use space heaters or cooling appliances, then you should definitely add insulation. This will cut down on the amount of energy you need to heat and/or cool the space. But if you only use your basement or garage for storage, and you're not trying to heat or cool the space, then you only need to insulate the walls that connect to the main building to stop heat travelling between them.