Home Insulation: It’s All About the R-Value
Whether you live in Bangor, Maine, or Bakersfield, California, your home will be more comfortable and energy efficient with the right insulation. Insulation helps lower the cost of heating and cooling your home. Here's how: Heat travels. In the winter, heat flows out; in the summer, heats flow in. A properly insulated home reduces that heat flow, so you don’t use as much energy to heat your home in the winter and cool it in the summer. Using less energy — or using energy more efficiently — could mean money in your pocket.
To help you get the most for your insulation dollar, the Federal Trade Commission (FTC) has answers to some basic questions about home insulation. As the nation’s consumer protection agency, the FTC enforces a number of energy-related laws, including the R-value Rule, which deals with insulation.
Q. What's the first thing I should look for when I buy insulation?
Look for the R-value. "R" means resistance to heat flow. The higher the R-value, the greater the insulating power. Almost all insulation products have to tell you their R-value — pipe and duct insulation are the only exceptions. (Duct wrap is covered.)
So, if you’re looking at insulation with an R-value of 38 from Company A and insulation with an R-value of 38 from Company B, you’ll know the two products offer the same level of insulation. That’s true even if they’re different kinds of insulation — say, if one is blanket insulation, which comes in batts and rolls, and the other is loose-fill insulation, which comes as loose fibers or fiber pellets and requires special equipment to blow it into a space.
Q. How do I know the R-value that’s appropriate for insulation in my home?
Several factors affect the R-value your home needs:
- Where you live. You'll need insulation with a higher R-value if you live in a cold climate like the Northeast than if you live in a warm climate like Southern California.
- How your home is built, and where the insulation will be. Is it a single-level or multi-level structure? Do you have cathedral ceilings? Is there a basement, or is your home built on a slab? Each of these factors helps determine the level of insulation your home needs.
- How you heat and cool your home. Whether you have a furnace, central air conditioner, or a heat pump can make a difference in your insulation decisions.
The Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE), has answers based on your zip code and information you enter about your home. Your local home improvement store (or its website) also may have information to help you determine your insulation needs.
Q. Should I use the same R-value of insulation throughout my home?
It's more efficient to use insulation with higher R-values in the attic and in rooms with cathedral ceilings than in wood frame walls, basements, or crawl spaces with walls.
A good way to see where energy is being wasted in your home is to do a home energy audit, which involves looking at your heating system, insulation, windows, doors, and other parts of your home to determine where you might be losing energy. You can do a basic walk-through yourself, or hire a professional to do a more thorough audit and make specific recommendations on how to make your house more energy efficient. Your utility company may offer free or low-cost energy audits, or may be able to recommend reputable local companies or organizations to do it.
Q. How do I know what R-value I'm getting?
The FTC enforces the R-value Rule, which ensures that you get accurate, honest information about the R-value of your insulation before you buy it, have it installed, or buy a new home. Manufacturers must label their packages of insulation; installers and retailers must provide fact sheets; and new home sellers must include this information in sales contracts.
Q. What should I do if I don't get information about the R-value from the manufacturer, retailer, installer, or new home seller?
Ask for the information. If no one provides it, consider buying it from someone else who will. Make sure to report it to the FTC. Use the online complaint form or call toll-free 1-877-FTC-HELP (382-4357).
This article was previously available as Home Insulation Basics: Higher R-Values = Higher Insulating.