Modern Style A Frame Home With Large Windows Covered In Snow

Non Fiberglass Insulation: Know Your Options

Sean Bryant6-Minute Read
March 01, 2021

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Have you ever noticed that a room in your home is always colder than the rest of the house? It’s most likely due to a lack of insulation in the walls or even the attic space above. Insulation allows the heat to stay in your home and prevents the cold winter air from getting in.

The Environmental Protection Agency’s Energy Star program estimates you can save as much as 15%, on average, on your heating and cooling costs, just by having the proper amount of insulation in your home. No matter if you need to insulate an attic, the walls, or even your garage, this is a critical step in winterizing a house.

But when it comes to insulation, there’s a lot to consider. You need to think about the R-value you need and the type of insulation you want to use (fiberglass vs. nonfiberglass insulation). Some can have a pretty steep price tag, while others are just cheap insulation with lower efficiency. We’re going to talk about each of these items so you’re more informed in case you need to improve a drafty room in your home.

The Downsides of Fiberglass

Fiberglass is the most common type of insulation found in homes. Made from small glass fibers, fiberglass insulation can be extremely irritable to a person’s skin and lungs. Because of that, it’s important to always wear protective gloves and a mask when working with fiberglass. Even though fiberglass can be cheap insulation, there are also several downsides that need to be considered.


  • Fiberglass insulation is a possible carcinogen. Fiberglass insulation packaging in the United States includes a warning that the product may have potential health risks. Some fiberglass insulation may contain formaldehyde, which is known to be a cause of cancer. If you’re installing fiberglass insulation without using a mask, you could be breathing in the tiny fiberglass particles, allowing them to stick to your lungs. Over time this can make it difficult to breath.
  • Fiberglass insulation can melt. Fiberglass insulation itself isn’t flammable, but for a long time, the paper backing companies used on rolls of insulation was. Today, most brands are using nonflammable materials. But while fiberglass insulation might not be considered flammable, it does have the ability to melt in a fire. When this happens, it can cause an increase in the oxygen supply which will accelerate a fire.
  • Fiberglass is not environmentally friendly. Once installed in a home, fiberglass insulation helps to save energy consumption. Unfortunately, the production of fiberglass insulation can take up to three times as much energy as other insulation types. This is why people who are looking to make eco-friendly changes to their home stay away from fiberglass when possible.
  • Reduced lifespan. Fiberglass insulation can be highly effective at reducing air transfer after installation. However, over time it starts to settle which reduces its R-value (more on R-value below) and effectiveness.

Terms To Know When Shopping

When you’re shopping for insulation, it’s important to have a basic understanding of some of the key insulation terms. Some of these items impact both the cost and effectiveness of different types of insulation.


R-value stands for the resistance the material has to heat transfer. The higher the R-value of your insulation, the more efficient it’s going to be. Depending on where you live in the United States, there are different building code requirements for the R-value needed. In colder climates, you’ll need a higher R-value compared to a home in a warmer climate. Energy Star has a guide for the recommended R-value in your area.


Off-gassing frequently happens with spray foam insulation. This occurs when the chemicals from a solid or liquid turn into gas while they’re in the air. These gases can be harmful if they’re inhaled. When using spray foam insulation in your home, it’s usually recommended that you avoid being inside for a period of time after installation.

Volatile Organic Compounds (VOC)

Volatile Organic Compounds (VOC) are both gases and odors that get omitted from insulation. The higher the VOC level, the more dangerous it is for a person to inhale it into their lungs. When searching for insulation, make sure you find something that has a low amount of VOCs.

Let a pro help.

Connect with a pro and get a home energy audit.

Non-Fiberglass Alternatives

Fiberglass is by far the most common type of insulation found in homes. It’s easily available and it’s easy on the wallet. But if you looking to stay away from putting fiberglass insulation into your home, there are several non-fiberglass alternatives you can choose from. Just be forewarned that none of these will fall into the category of cheap insulation, but most are better for the environment and your home.

Cellulose Insulation

  • Ideally used for: Cellulose insulation is great for anyone looking to use insulation made with recycled materials that are both fire and pest retardant.
  • Cost: $1.20 per square foot
  • R-value range: Between R-3.2 and R-3.8 per inch
  • Pros: The biggest benefit to using cellulose insulation is that it’s made from 75% to 85% recycled newspaper. This makes it extremely environmentally friendly compared to other insulation materials. It’s treated with boric acid which helps repel insects and rodents. Cellulose insulation has an average VOC rating of 101 µg/m3 which is significantly lower than what most consider to be “low VOC.”
  • Cons: Installing cellulose insulation isn’t a DIY-friendly project. Because it’s blown, it can create a substantial amount of dust and it’s better to have it professionally installed. Cellulose insulation isn’t recommended for humid environments because it can retain moisture more easily than other types of insulation. This can increase the chances of mold.

Soy Insulation

  • Ideally used for: Soy insulation is a great option when you’re looking for something that contains no formaldehyde and will not off-gas any chemical byproducts.
  • Cost: Open cell soy insulation costs $0.44 to $0.65 per foot. Closed-cell soy insulation costs $0.70 to $1.00 per foot
  • R-value range: Open cell has an R-value of 3.6 per inch. Closed-cell has an R-value of 6.5 per inch.
  • Pros: The biggest advantage to soy insulation is that it doesn’t give off any off-gases, which means it’s much healthier. It also does a great job of repelling rodents from the home. Because it’s a spray foam insulation, it will expand in size, filling hard to insulate areas, leading to a more energy-efficient home.
  • Cons: There’s a high upfront cost to install soy insulation. However, over time, the energy savings will begin the make up for the initial expense.

Spray Foam Insulation

  • Ideally used for: Spray foam is a great choice if you’re looking for insulation alternatives and want optimal energy efficiency in your home.
  • Cost: Spray foam insulation is available in two forms, open cell and closed cell. Open-cell spray foam costs between $0.44 and $0.65 per foot. Closed-cell spray foam costs between $1.00 and $1.50 per foot.
  • R-value range: Open cell spray foam has an R-Value around 3.7 per inch and closed-cell can reach up to 6.5 per inch.
  • Pros: Spray foam insulation is great at filling all the little cracks and crevices. Once it’s sprayed into walls, it will expand, trapping moisture and air out. It’s also great at reducing noise transfer from the exterior of a home. Plus, as long as there are no moisture leaks, it will last much longer than other types of insulation.
  • Cons: Spray foam insulation can produce off-gases that can last anywhere from 24 to 72 hours after installation. Professional installation is recommended so it’s not ideal for the DIYer. Spray foam can also have a greater upfront cost compared to fiberglass insulation.

Natural Fiber Batts

  • Ideally used for: Using natural fiber batt insulation is ideal for anyone looking to create a green home.
  • Cost: The cost of different natural materials can vary but cotton batt insulation typically costs around $1.20 to $1.50 per square foot
  • R-value range: R-3.6 per inch
  • Pros: Different types of natural fiber batt insulation have very high longevity. For example, cotton can last up to 100 years without breaking down and becoming ineffective. Natural fiber insulation is also one of the most eco-friendly types of insulation. Cork even has a negative carbon footprint.
  • Cons: Most natural fiber insulation is quite a bit more expensive than fiberglass. It also has a slightly lower R-value. If natural fiber insulation is left untreated, it has a tendency to attract moths and other insects. However, most manufacturers today will treat the insulation with an eco-friendly solution.

Let a pro help.

Connect with a pro and get a home energy audit.

The Bottom Line

If you have a drafty room in your house or looking to build an addition, installing insulation is going to be one of the most important things you do for energy efficiency. When it comes to choosing a type of insulation, there’s a lot to consider. While fiberglass tends to be the most common, non-fiberglass insulation is growing in popularity because many are safer for the environment and healthier for our homes. A lot of home improvement projects, including insulation, can be complex. Make sure you stay up to date with the Rocket Homes® blog to learn more. 

Sean Bryant

Sean Bryant is a Denver based freelance writer specializing in travel, credit cards, and personal finance. With more than 10 years of writing experience, his work has appeared in many of the industries’ top publications.