Your attic might be where you put something to forget about it. You shouldn’t forget about your attic’s insulation though, as doing so can inflate your energy bills and make your home less comfortable.
Insulating your attic and the rest of your home’s envelope can shave 11% off your home energy bills, according to the US Environmental Protection Agency. Insulating an attic for the first time or refreshing existing insulation by adding more is a job you can hire out or tackle on your own. Here’s what you need to know.
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How Does Insulating Your Attic Save You Money?
Compared to a poorly insulated or uninsulated attic, a well-insulated one prevents heat loss in the winter and heat gain in the summer. That means your HVAC system doesn’t need to work as hard in both the heating and cooling seasons. The less energy you need to heat or cool your home, the less energy you need to buy.
How much you actually save depends on a number of factors, like the state of your attic’s insulation to start and how well-insulated the rest of your home is. Further, the cost of the project will vary depending on whether you do it yourself or hire a professional, the size of your attic, and the strength of insulation your region requires.
Attic Insulation Can Make You More Comfortable
Beyond the bill savings, attic insulation can keep you more comfortable by keeping your home’s temperature steadier, especially on a second story.
Rooms on the top (or only) floor of your home won’t lose heat as quickly in the winter or gain it as quickly in the summer, keeping them and the rest of your home more comfortable.
Can You Insulate an Attic on Your Own?
Hiring a professional may get you better results (and make your life easier!), but you can insulate your own attic with a bit of know-how.
Where to insulate
Insulation should be installed where it acts as a barrier between the conditioned part of your home and the unconditioned outdoors. For many homes, the attic and the open space under the roof are uninsulated since they’re designed to vent hot air in the summer.
If you have an unconditioned attic, you’ll add insulation between the floor joists and the attic access door. In attics you want to heat and cool with the rest of your house, you’ll need insulation in finished walls, in any knee walls, and under the roof or in ceilings between the attic and unconditioned spaces.
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What type of insulation should you install?
Attics are commonly insulated with roll batt insulation or loose fill insulation that can be blown in to cover the floor. Blow-in insulation can be evenly spread to a depth of 10-13 inches.
The performance of insulation is measured by its R-value. The higher the R-value, the better it does at keeping heat in or out. The R-value your attic needs depends on where you live.
| Climate Zone | Uninsulated Attic | 3-4 inches of Existing Attic Insulation |
|---|---|---|
| 1 | R30–R49 | R19–R38 |
| 2-3 | R49–R60 | R38–R49 |
| 4-8 | R60 | R49 |
Source: US Department of Energy
How to install insulation
If you’re considering tackling this project yourself, here’s how to do it in general terms. Each attic could vary.
- Preparation: Before installing insulation, check for leaks or gaps in the attic that might compromise the insulation’s effectiveness. Seal cracks or gaps in the attic floor and ensure the attic is dry to avoid mold or mildew.
- Choose your insulation: Decide on the insulation type that works best for your home and budget. Batt and blow-in insulation are good options for standard attic spaces. Spray foam may be more effective for tighter spaces or those needing air sealing.
- Installation: Measure the area to determine how much insulation is needed. Then, lay the batts or blow in the insulation to the desired depth.
Remember to wear protective clothing. Wear gloves to protect your hands and a mask to avoid inhaling insulation dust or fibers.
Be honest with yourself about your abilities. Poorly installed installation won’t work as well, and hiring a professional could save you time and improve your comfort in the long run.
When Should You Insulate Your Attic?
There’s very rarely a good reason to wait to install insulation once you notice it's lacking. Here are a few times you should add insulation to your attic.
- Uninsulated attic: If your attic has never been insulated, insulation is sure to improve your energy efficiency.
- Building or renovating: New construction and renovation projects that open access to your attic are good opportunities to address insulation issues.
- Rising energy bills: If your energy bills are higher than typical, especially during the heating and cooling seasons, your insulation may be in need of a refresh. (Rising energy costs and weather could be culprits, too.)
- Uncomfortable indoor spaces: If the rooms below your attic are uncomfortably hot in the summer or cold in the winter, improving your attic insulation may help.
Attic insulation is often called one of the best ways to improve your home’s energy efficiency. The sooner you install it, the sooner you can start reaping its benefits, like lower energy bills and a more comfortable home. Get a free estimate of how much you could save with home energy changes.
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Frequently Asked Questions
Can insulating your attic save you money?
Insulating your attic can reduce your energy bill if it is not insulated or poorly insulated to start.
Why is attic insulation important?
Attic insulation is an important part of your home’s envelope — the parts of your house that separate the air-conditioned part of your home from the outdoors. The barrier between your attic and the interior of your home can be a major avenue for unwanted heat leaving or entering your home. Insulating that barrier can slow that exchange.
How can I make my home energy efficient?
Depending on the current state of your home, you can improve its efficiency by boosting your insulation, blocking leaks and drafts with weatherstripping, installing energy-efficient appliances, and strategically using smart devices like smart thermostats and smart plugs.
Andrew BlokWriter and EditorAndrew has worked as a journalist and writer for four years, over half of those dedicated to covering solar. He currently lives in Tucson, AZ, where you might run into him walking his dog and birding while dodging the heat. He has degrees in English education and journalism.
