Cellulose Insulation: What It Is, Costs & How It Compares

Cellulose insulation is one of the most eco-friendly and cost-effective ways to insulate a home, yet many homeowners know little about it compared to fiberglass or spray foam. Made largely from recycled paper, cellulose fills gaps and resists air movement in a way that makes it a strong performer, especially for attics and existing homes. Understanding what cellulose is, what it costs, and how it stacks up against other options helps you decide whether it is the right fit. This guide walks through all three.

Here is what you will learn:

• What it is: How cellulose insulation is made and how it works.
• The cost: What cellulose insulation typically runs.
• How it compares: Cellulose versus fiberglass and spray foam.

What Is Cellulose Insulation?

Cellulose is a distinct insulation material with an eco-friendly makeup and solid performance. Understanding the basics explains its appeal.

A Recycled, Eco-Friendly Material

Cellulose insulation is made primarily from recycled paper, treated with safe chemicals for fire and pest resistance, making it one of the greenest insulation options available. According to the U.S. Department of Energy’s Building America Solution Center, cellulose is made from recycled newspaper and boxes with a recycled content of roughly 82 to 85 percent, far higher than most alternatives. The paper is treated with borate for fire and pest resistance, then blown into attics and wall cavities. For homeowners across Waukee and surrounding areas who value sustainability, cellulose stands out for its high recycled content.

• Recycled paper: Made largely from newspaper and boxes.
• High recycled content: Roughly 82 to 85 percent recycled material.
• Treated for safety: Borate adds fire and pest resistance.
• Eco-friendly: One of the greenest insulation options.

How Cellulose Insulation Performs

Cellulose is a dense material with a solid R-value that resists both heat transfer and air movement, giving it strong real-world performance. Its R-value is typically around 3.2 to 3.8 per inch, and because it is dense and fills gaps thoroughly, it reduces air infiltration better than many materials of the same rating. This density makes it especially effective in attics and when dense-packed into walls. The combination of solid R-value and air resistance is what makes cellulose a strong performer.

• Solid R-value: Around 3.2 to 3.8 per inch.
• Dense material: Resists air movement, not just heat.
• Fills gaps: Conforms around framing and wiring.
• Strong performer: Effective in attics and walls.

5 Benefits of Cellulose Insulation

The benefits below are the main reasons homeowners choose cellulose. This section introduces them, then breaks each one down so you can see what you gain.

1. Excellent Eco-Friendliness

Cellulose has the highest recycled content of any common insulation, making it the clear choice for environmentally conscious homeowners. Made from roughly 82 to 85 percent recycled paper, it diverts waste from landfills and takes relatively little energy to manufacture compared to furnace-produced materials like fiberglass. For homeowners who want to reduce their environmental footprint, cellulose is hard to beat. That green profile is one of its biggest draws.

• Highest recycled content: More than most insulations.
• Diverts waste: Keeps paper out of landfills.
• Low embodied energy: Takes little energy to produce.
• Green choice: Ideal for eco-conscious homeowners.

2. Strong Air-Sealing Performance

Because cellulose is dense and fills cavities thoroughly, it reduces air infiltration better than many insulations with the same R-value. Air movement through gaps is a major source of energy loss, and cellulose’s density helps block it, conforming around wiring, framing, and irregular spaces. This means better real-world comfort and efficiency than the R-value alone suggests. That air-sealing ability is a practical, money-saving benefit.

• Dense and thorough: Fills cavities completely.
• Reduces air infiltration: Blocks a major source of energy loss.
• Conforms well: Fits around framing and wiring.
• Real-world efficiency: Outperforms its R-value rating.

3. Great for Existing Homes

Blown-in cellulose is ideal for adding insulation to existing homes, since it can be installed into attics and even into closed wall cavities with minimal disruption. It is commonly blown on top of existing attic insulation to reach a higher R-value, and dense-pack cellulose can be added to walls through small access holes. This makes it a go-to for retrofits and upgrades. For an older home needing better insulation, cellulose is often the practical choice.

• Retrofit-friendly: Great for upgrading existing homes.
• Tops off attics: Blown over existing insulation easily.
• Dense-pack walls: Fills closed cavities with minimal disruption.
• Practical upgrade: A go-to for older homes.

4. Good Fire and Pest Resistance

Cellulose is treated with borate, which gives it effective resistance to fire, insects, and mold, countering a common misconception about paper-based insulation. The borate treatment makes the material resistant to ignition and unappealing to pests, and it helps resist mold growth. Properly installed and treated cellulose meets fire-safety standards. That treated resistance makes cellulose a safe, durable choice.

• Borate treatment: Resists fire, pests, and mold.
• Meets standards: Properly treated to fire-safety codes.
• Pest-resistant: Unappealing to insects.
• Dispels the myth: Treated cellulose is not a fire risk.

5. Cost-Effective Value

Cellulose offers strong insulating performance at an affordable price, making it one of the best values in home insulation. It costs less than spray foam while often outperforming fiberglass in real-world air sealing, giving homeowners excellent return for the money. Paired with the energy savings it delivers, cellulose is a budget-friendly upgrade that pays off. That value is a major reason homeowners choose it.

• Affordable: Costs less than spray foam.
• Strong performance: Often beats fiberglass in air sealing.
• Good ROI: Energy savings offset the cost.
• Budget-friendly: One of the best values in insulation.

How Much Does Cellulose Insulation Cost?

Cost is a key consideration, and cellulose is among the more affordable insulation options. Here are realistic 2026 ranges.

Typical Cellulose Insulation Costs

Blown-in cellulose is an affordable insulation upgrade, especially for the energy savings it returns. According to HomeGuide, blown-in cellulose typically costs about $1 to $2.30 per square foot installed, with a typical attic project running roughly $1,500 to $3,000 depending on size and target R-value. Dense-pack cellulose for walls sits at the higher end of that range. For homeowners in Waukee and surrounding areas, an itemized estimate based on your home gives the real figure.

• Affordable: Roughly $1 to $2.30 per square foot installed.
• Typical attic: About $1,500 to $3,000.
• Dense-pack: Wall applications cost a bit more.
• Get an estimate: Your home’s size sets the price.

What Affects Your Cost

The cost of a cellulose project depends on the size of the area, the target R-value, whether it is a loose-fill attic or dense-pack wall application, and your home’s accessibility. Reaching a higher R-value requires more material, and dense-packing walls takes more labor than blowing an open attic. Removing old insulation, if needed, adds to the total. An itemized estimate shows exactly what drives your price.

• Area size: More square footage raises the total.
• Target R-value: Higher R-values need more material.
• Application: Dense-pack walls cost more than attics.
• Extras: Old insulation removal adds cost.

How Does Cellulose Compare to Other Insulation?

For most homeowners, the real decision is cellulose versus fiberglass or spray foam. A direct comparison helps.

Cellulose Versus Fiberglass

Cellulose and fiberglass are the two most common blown-in options, and cellulose generally offers better air sealing while fiberglass resists moisture better. Cellulose is denser, with a slightly higher R-value per inch and better resistance to air infiltration, while fiberglass is lighter, is not permanently damaged by water, and often costs a bit less. Both are affordable and effective for attics. The choice often comes down to prioritizing air sealing and recycled content versus moisture resistance and cost.

• Cellulose wins: Better air sealing and recycled content.
• Fiberglass wins: Better moisture resistance, often lower cost.
• Both effective: Strong, affordable attic options.
• Your priorities: Air sealing versus moisture and price.

Cellulose Versus Spray Foam

Spray foam offers the highest R-value per inch and the best air sealing, but it costs significantly more than cellulose. Spray foam creates an air barrier and excels in certain applications, but it typically costs several times what cellulose does and requires professional installation. Cellulose delivers strong air sealing and solid R-value at a fraction of the price. For many homeowners, cellulose provides most of the benefit for much less money, while spray foam is worth it where maximum performance is the priority.

• Spray foam leads: Highest R-value and air sealing.
• Much pricier: Several times the cost of cellulose.
• Cellulose value: Strong performance for far less.
• The trade-off: Maximum performance versus cost.

Frequently Asked Questions

What is cellulose insulation made of?

Cellulose insulation is made primarily from recycled paper, mainly newspaper and cardboard, with a recycled content of roughly 82 to 85 percent. It is treated with borate for fire and pest resistance. This high recycled content makes it one of the most eco-friendly insulation options available.

How much does cellulose insulation cost?

Blown-in cellulose typically costs about $1 to $2.30 per square foot installed, with a typical attic project running roughly $1,500 to $3,000 depending on size and target R-value. Dense-pack wall applications cost a bit more. A professional estimate gives an accurate figure for your home.

Is cellulose insulation better than fiberglass?

Cellulose generally offers better air sealing and higher recycled content, while fiberglass resists moisture better and often costs slightly less. Both are effective, affordable attic options. The better choice depends on whether you prioritize air sealing and sustainability or moisture resistance and cost.

Is cellulose insulation a fire hazard?

No. Cellulose is treated with borate, which gives it effective fire resistance and meets fire-safety standards when properly installed. The common belief that paper-based insulation is a fire risk is a misconception. The borate treatment also resists pests and mold.

Can cellulose insulation get wet?

Cellulose can absorb moisture if directly exposed to water, so it should be kept dry and installed where it will not get wet. In normal conditions with proper installation, this is not an issue. If cellulose does get soaked, it should be assessed and may need replacement.

Is cellulose good for attic insulation?

Yes. Cellulose is one of the most popular and effective choices for attic insulation because it is dense, fills gaps well, reduces air infiltration, and is affordable. It can be blown over existing insulation to reach a higher R-value. For many homes, it offers excellent value.

Why Heartland Is a Smart Choice for Your Cellulose Insulation

Insulation is one of the highest-return upgrades you can make in your home, and proper installation is what delivers the full comfort and energy savings. Heartland Roofing, Siding & Solar helps homeowners across Waukee and surrounding areas choose the right insulation for their home and goals and installs it to reach the R-value Iowa’s climate calls for, all with honest, educational guidance rather than high-pressure sales. With an A+ BBB rating and a commitment to quality workmanship, Heartland makes sure your insulation performs as it should. Reach out to Heartland today for a free inspection and expert guidance on your cellulose insulation.