The main image is courtesy of Owens Corning which illustrates several types and locations of insulation.

Maintaining a comfortable temperature in your home can be difficult and costly if you don’t have well-performing insulation. Properly chosen and installed home insulation is essential for keeping the heat inside during winter and outside during summer. Effective insulation also helps to keep energy costs down by maintaining consistent temperatures throughout the year.

Given the importance of insulation, homeowners need to understand which type works best for their homes, and when they may need to replace existing insulation. Following this guide, homeowners can make informed decisions about their home’s insulation needs and ensure that their homes are well insulated all year round.

Table of Contents

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What is Home Insulation?

Home insulation is material that stops heat transfer in and out of a home. Insulation can consist of a wide range of materials, such as fiberglass, cellulose, foam board, and rigid foam. Each type of insulation has pros and cons, so homeowners need to be familiar with the various traits and tradeoffs to understand which type would best suit their needs.

Effective insulation will enable your home to maintain consistent indoor temperatures which means that your heating and cooling systems will not have to work as hard, or as frequently. To maintain comfort, the warm air lost during the winter must be replaced by your heating system, while the heat gained during the summer will need to be removed by your cooling system. Properly insulating your home will decrease this year-round heat flow by providing an effective resistance to the flow of heat, measured by its R-value.

How Home Insulation Works

Home insulation works by slowing the transfer of heat between the inside and outside of your home, keeping it warm in winter and cool in summer. Insulation materials, like fiberglass, cellulose, or foam, trap air or create barriers that resist heat flow through walls, attics, and floors. This reduces the need for heating and cooling, lowering energy bills. Proper installation is key to avoid gaps or compression, ensuring your home stays comfortable and energy-efficient year-round.

Understanding R-Value in Insulation

The effectiveness of insulation is measured by its R-value. The R-value of a given insulation material is a measurement of its resistance to heat flow, from warmer to colder areas, specifically rated in terms of its thermal resistance. The higher the R-value, the greater the effectiveness of the insulation. The R-value will depend on the type of insulation, thickness, and density.

The R-value needed for effective home insulation depends on your home’s specific requirements. Your local climate plays a major role, with colder areas generally needing higher R-values and milder climates managing with lower ones.

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Types of Insulation

There are several different types of insulation. Here are the most widely used insulation types:

  1. Fiberglass Insulation
  2. Cellulose Insulation
  3. Foam Board Insulation
  4. Spray Foam Insulation
  5. Mineral Wool Insulation
  6. Radiant Barrier Insulation

 

1. Fiberglass Insulation

Fiberglass insulation comprises of small glass fibers and comes as batting or loose fill. It is a popular choice among homeowners due to its:

  • Affordability
  • Availability
  • Ease of Installation
Contractor installing Owens Corning fiberglass insulation

Image courtesy of Owens Corning

Summary of Fiberglass Insulation Traits:

  • Cost: $0.30–$1.50 per square foot (batts or rolls); $1.00–$2.50 per square foot (blown-in).
  • R-Value Range: R-2.9 to R-3.8 per inch (batts); R-3.1 to R-4.3 per inch (blown-in).
  • Best Use Cases:
    • Walls, attics, floors, and crawl spaces in new or existing homes.
    • DIY-friendly for accessible areas like attics or unfinished walls.
  • Pros:
    • Affordable and widely available.
    • Non-combustible (without facing material).
    • Easy to install (batts/rolls) for DIY projects.
    • Recyclable and often contains recycled content.
  • Cons:
    • Can irritate skin, eyes, and lungs during installation (requires protective gear).
    • Loses effectiveness if compressed or exposed to moisture.
    • Lower R-value per inch compared to foam-based options.
    • May settle over time (blown-in).

Top Fiberglass Insulation Brands and Products

 

2. Cellulose Insulation

Made from recycled materials, such as newspapers and cardboard, cellulose insulation is a popular choice for its eco-friendly credentials. It’s also fire-resistant and effective at stopping air leaks.

Cellulose insulation sample

Summary of Cellulose Insulation Traits:

  • Cost: $0.60–$1.80 per square foot (blown-in or dense-pack).
  • R-Value Range: R-3.1 to R-3.8 per inch.
  • Best Use Cases:
    • Attics, walls, and floors, especially in retrofitting existing homes.
    • Ideal for irregular or hard-to-reach spaces (blown-in).
  • Pros:
    • Made from recycled paper (eco-friendly).
    • Good soundproofing and air-sealing properties.
    • Treated for fire and pest resistance.
    • Effective at filling gaps and voids.
  • Cons:
    • Can settle over time, reducing R-value.
    • Absorbs moisture, potentially leading to mold if not properly managed.
    • Requires professional installation for dense-pack applications.
    • Dust and mess during installation.

Top Cellulose Insulation Brands and Products

 

3. Foam Board Insulation

Foam board insulation consists of rigid panels made from polystyrene, polyisocyanurate or polyurethane installed in walls, floors, and ceilings. This can be an effective type of insulation, but it can be expensive and time-consuming to install.

Rigid foam board insulation is commonly used in exterior wall assemblies (AKA exterior continuous insulation) and for below-grade walls, such as in basements and crawlspaces.

Rigid foam board insulation being installed on the exterior of a house

Summary of Foam Board Insulation Traits:

  • Cost: $0.70–$2.00 per square foot (depending on thickness and material, e.g. polystyrene, polyisocyanurate).
  • R-Value Range: R-3.6 to R-8.0 per inch (varies by type: EPS ~R-4, XPS ~R-5, polyiso ~R-6–8).
  • Best Use Cases:
    • Exterior walls, foundations, basements, and under slabs.
    • Cathedral ceilings or areas needing thin, high R-value insulation.
  • Pros:
    • High R-value per inch, allowing thinner applications.
    • Moisture-resistant (especially XPS).
    • Provides a continuous insulation layer, reducing thermal bridging.
    • Lightweight and easy to cut/install.
  • Cons:
    • Higher cost than fiberglass or cellulose.
    • Requires careful sealing to prevent air leaks.
    • Can be damaged by UV exposure or physical impact.
    • Some types (e.g. polyiso) lose R-value in very cold climates.

Top Foam Board Insulation Brands and Products

 

4. Spray Foam Insulation

Spray foam insulation is made from polyurethane and used to fill in cracks and crevices. It provides a tight seal that can help reduce air leakage, but it can be expensive and may need to be professionally installed.

Contractor installing spray foam insulation in an attic

Summary of Spray Foam Insulation Traits:

  • Cost: $1.00–$4.50 per square foot (open-cell: $0.50–$1.50; closed-cell: $1.50–$4.50).
  • R-Value Range: Open-cell: R-3.5 to R-3.6 per inch; Closed-cell: R-6.0 to R-7.0 per inch.
  • Best Use Cases:
    • Walls, attics, crawl spaces, and rim joists.
    • Ideal for sealing air leaks in irregular or hard-to-reach areas.
    • Closed-cell foam for areas needing moisture resistance (e.g., basements).
  • Pros:
    • High R-value (especially closed-cell).
    • Excellent air-sealing and moisture barrier (closed-cell).
    • Expands to fill gaps, improving energy efficiency.
    • Adds structural strength (closed-cell).
  • Cons:
    • Expensive, especially closed-cell.
    • Requires professional installation.
    • Potential off-gassing of chemicals during curing (ventilation needed).
    • Not eco-friendly (high embodied energy, non-recyclable).

 

5. Mineral Wool Insulation

Mineral wool insulation is made from rock or slag wool and comes in batts or loose-fill. This type of insulation has a high R-value, is fire-resistant and is resistant to moisture and can prevent mold growth. It is typically more expensive than other types of insulation.

Contractor installing Rock Wool mineral wool insulation

Image courtesy of Rockwool

Summary of Mineral Wool Insulation Traits:

  • Cost: $0.60–$2.00 per square foot (batts or loose-fill).
  • R-Value Range: R-3.0 to R-3.3 per inch (batts); R-2.8 to R-3.7 per inch (loose-fill).
  • Best Use Cases:
    • Walls, attics, and floors in residential or commercial buildings.
    • High-temperature areas (e.g. near fireplaces or chimneys).
    • Soundproofing for interior walls.
  • Pros:
    • Fire-resistant (can withstand temperatures over 1,000°F).
    • Excellent soundproofing.
    • Moisture-resistant and mold-resistant.
    • Made from recycled materials (slag or basalt).
  • Cons:
    • More expensive than fiberglass or cellulose.
    • Heavier and less flexible, making installation trickier.
    • Can irritate skin/lungs during installation (protective gear needed).
    • Slightly lower R-value per inch than foam options.

 

6. Radiant Barrier Insulation

Radiant barrier insulation is installed in the attic and reflects heat from the sun away from the home. This type of insulation is typically made from aluminum foil or plastic films with reflective surfaces, and has a low R-value. Radiant barrier insulation is effective in hot climates as it will keep your home cooler during the hot months, which will reduce your cooling costs.

Contractor installing RadiaSource radiant barrier insulation in attic

Image courtesy of RadiaSource

Summary of Radiant Barrier Insulation Traits:

  • Cost: $0.10–$0.50 per square foot (foil or paint-on barriers).
  • R-Value Range: Not typically rated by R-value; effectiveness depends on reducing radiant heat transfer (measured by emissivity, typically 0.03–0.05).
  • Best Use Cases:
    • Attics in hot climates to reflect radiant heat from the roof.
    • Often paired with other insulation types for combined benefits.
    • Garage doors or exterior walls in sunny regions.
  • Pros:
    • Reduces cooling costs in hot climates (up to 10–15% energy savings).
    • Inexpensive and easy to install (foil sheets or paint).
    • Lightweight and non-invasive.
    • Durable and maintenance-free.
  • Cons:
    • Limited effectiveness in cold climates (not a true insulator).
    • Requires an air gap to work effectively.
    • Minimal impact without direct sunlight exposure.
    • Not a standalone insulation solution; must be combined with other materials.

According to the US Department of Energy, some studies have shown that radiant barriers can reduce energy costs by 5% to 10% in warm sunny climates. The reduced heat gain may also allow for the use of a smaller air conditioning system.

However, this type of insulation is not effective in cold climates. Also the type and layout of your roof (e.g. slope; roof shingles; ventilation) will all have an impact on how much heat can be reflected.

These are just a few types of insulation homeowners should consider when deciding what type to install in their homes.

 

Notes on Insulation Comparison Traits

  • Cost Variations: Prices depend on labor, region, and whether installation is DIY or professional. Check local suppliers or contractors for precise quotes.
  • R-Value Context: Higher R-values indicate better thermal resistance, but effectiveness depends on proper installation, air sealing, and climate.
  • Climate Considerations: Choose insulation based on your climate (e.g. radiant barriers for hot climates; high R-value materials like spray foam for cold climates).
  • Sustainability: Cellulose and mineral wool often have higher recycled content, while spray foam and foam board have higher environmental footprints.

 

Where to Install Home Insulation

Knowing where to install insulation in your home is just as important as choosing the right material. Each area of your house loses or gains heat differently, so the placement of insulation plays a major role in energy efficiency, comfort, and long-term savings. Below are the most common locations where insulation makes the biggest impact.

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Attic Insulation

The attic is usually the most cost-effective place to add insulation, since heat naturally rises and escapes through the roof. Adding attic insulation helps reduce both heating and cooling costs.

  • Loose-fill insulation (often cellulose or fiberglass) is ideal for filling in irregular or hard-to-reach spaces and is commonly blown in by professionals.
  • Batt insulation (pre-cut fiberglass or mineral wool panels) works well between joists and is a practical option for DIY installation.

 

Wall Insulation

Insulating walls is crucial for maintaining consistent indoor temperatures and reducing drafts. The approach depends on whether your home is new or existing:

  • New construction allows insulation to be placed directly between studs, typically with fiberglass batts, spray foam, or mineral wool.
  • Retrofit wall insulation in older homes often involves blown-in insulation through small holes drilled in the drywall or siding. Spray foam insulation can also be used for superior air sealing in problem areas.

 

Floor and Crawl Space Insulation

Uninsulated floors and crawl spaces can create cold spots and lead to higher energy bills. Moisture control is especially important in these areas to prevent mold and rot.

  • Fiberglass batts are commonly installed between floor joists.
  • Rigid foam board insulation is effective for crawl space walls and provides a moisture-resistant barrier while improving energy efficiency.

 

Basement and Foundation Insulation

Basements and foundations often lose heat through contact with cold soil, so below-grade insulation is key. Proper installation also helps prevent condensation and moisture issues.

  • Rigid foam boards or spray foam are frequently used along basement walls to stop air leaks and resist moisture.
  • Adding insulation to rim joists and sill plates can significantly reduce drafts and improve comfort on the main floor.

 

Roof Insulation

If your roof structure allows, insulating directly under the roof deck is another way to boost efficiency. The method depends on roof design:

  • Ventilated roofs typically rely on insulation at the attic floor, with ventilation channels above to allow airflow.
  • Unventilated roofs (such as cathedral ceilings) benefit from spray foam insulation, which both insulates and creates an airtight seal against moisture.

 

Best Insulation by Home Area Comparison Table

Use this quick reference chart to see the best insulation options for each area of your home, along with their key benefits and important considerations.

Home Area Best Insulation Options Key Benefits Considerations
Attic Loose-fill (cellulose/fiberglass), Batts (fiberglass/mineral wool) Cost-effective, fills gaps, improves heating/cooling efficiency Loose-fill usually requires professional installation
Walls Blown-in cellulose, Spray foam, Fiberglass batts Reduces drafts, maintains indoor temps, great retrofit option Spray foam costs more but provides superior air sealing
Floors & Crawl Spaces Fiberglass batts, Rigid foam boards Prevents cold floors, moisture control, improves comfort Must address moisture/vapor barriers to avoid mold
Basement & Foundation Rigid foam boards, Spray foam Stops heat loss through foundation walls, moisture resistant Below-grade areas need proper drainage and sealing
Roof Spray foam (unventilated roofs), Attic floor insulation (ventilated roofs) Air sealing, prevents condensation, long-term savings Roof type determines best approach; pro install often required

 

By understanding where to install insulation and matching the right material to each area of your home, you can maximize energy savings, improve comfort, and extend the lifespan of your living spaces.

 

Installing Home Insulation

It’s essential to ensure proper insulation installation so that it works effectively. The type of insulation homeowners choose will depend on the space the insulation is needed in, the climate they live in, and their budget.

Roll of fiberglass insulation and installation supplies and tools

Homeowners may install their insulation if they feel comfortable or hire a professional for more complex installations. According to insulation experts at iFOAM:

“Proper insulation can make the air you breathe healthier and more comfortable.”

 

When to Replace Your Existing Insulation

Homeowners also need to be aware of when their home’s insulation needs replacing. When it becomes time to replace your existing insulation, the material will often appear to be wet, thinning, or generally broken down. Also, insulation can fall or be dislodged from its original positioning, which will further hinder its effectiveness.

Signs that it may be time to replace your insulation include:

  1. High Energy Bills
  2. Uneven Temperatures in the Home
  3. Visible Damage or Deterioration
  4. Age of Insulation
  5. Outside Noises

 

1. High Energy Bills

If your energy bills are higher than average, it could be a sign that your home’s insulation is not working effectively. Given that changes in energy usage and corresponding costs may be subtle month-to-month, or even year-over-year, be sure to keep historic annual records to check for more significant changes (e.g. going back a few years).

 

2. Uneven Temperatures in the Home

Poorly insulated homes can lead to noticeable uneven temperatures throughout the house, making it challenging to regulate the indoor climate.

Thermal imaging camera being used inside an empty house

 

3. Visible Damage or Deterioration

Your insulation may need replacing if you see any signs of damage in your home’s insulation, such as falling, thinning or broken pieces.

 

4. Age of Insulation

Insulation should be replaced every 10-15 years, as it can break down over time and lose its effectiveness. As part of staying abreast of the overall health and condition of your home be sure to keep household records on the age and expected lifespans of key components and elements of your home. Knowing when you are in the later years of your insulation’s expected lifespan can make replacement an easier decision to make.

 

5. Outside Noises

If you start noticing more sounds and noises from outside your home through your walls and floors, this could be an indication that your insulation needs replacing. Besides impeding heat flow, insulation also provides sound insulation between rooms and from outside your home.

Ignoring any of these signs can put you at risk of losing money in the form of higher energy bills and incurring damage to your home. Take the time to assess your home’s insulation needs proactively, taking action when possible, or seeking outside professional assistance when unsure of which course to take.

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Benefits of Home Insulation

  1. Improved Comfort Levels
  2. Better Air Quality
  3. Noise Reduction
  4. Increase in Home Value
  5. Greater Energy Efficiency

 

1. Improved Comfort Levels

One of the main benefits of home insulation is the improved comfort levels it provides. Insulation helps maintain a consistent temperature throughout the house, so you’ll no longer experience hot or cold spots. This makes your home more comfortable and reduces the strain on your heating and cooling systems, which could lead to lower energy bills.

Homeowner enjoying a comfortable indoor climate

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2. Better Air Quality

Home insulation has many benefits, and one of the most essential advantages is improving the air quality inside the house. Home insulation ensures that there is less leakage of air, which inhibits contaminants from entering the house. With proper insulation, households can maintain air quality by significantly reducing levels of allergens and pollutants, which can lead to respiratory problems.

As a result, the health of residents is not compromised, and the risk of illness is minimized. Reduced air leakage also leads to lower energy consumption due to consistent indoor temperatures, making the house more sustainable and eco-friendly.

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3.  Noise Reduction

Insulating your home can also help reduce noise levels. The insulation acts as a sound barrier, preventing unwanted noises from entering the house and protecting you from outside disturbances. This means you can enjoy peace and quiet in your home without being disturbed by external noises.

 

4. Increase in Home Value

Home insulation can also add to the value of your house. Installing proper insulation is a great way to ensure your house is energy-efficient and can help you get a higher price if you decide to put it on the market.

 

5. Greater Energy Efficiency

Finally, investing in home insulation can make your home more energy-efficient. By installing proper insulation, you will be taking steps to ensure that your house consumes less energy, which reduces the amount of electricity and other resources needed to keep it running. This will result in lower utility bills and reduced environmental impact.

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How Much Does Insulation Cost?

Home insulation costs depend on the size and type of insulation. It also depends on the area being insulated and whether any additional work needs to be done.

According to a recent Forbes article:

The average cost of home insulation is between $3,000 and $10,000 for a 2,000 square foot home, or between $1.50 and $5.00 per square foot.

Generally, it costs less to protect a more prominent space because you can use fewer materials in larger areas. Some types of insulation require additional labor for installation, which can increase the cost.

In conclusion, home insulation is a great way to make your house more comfortable, healthy, and energy-efficient. It also adds value to your property, which can be beneficial when selling. Therefore be sure to take time to assess your home’s insulation needs and consider investing in proper insulation to reap all these benefits.

 

Top Insulation Manufacturers

 

Frequently Asked Questions (FAQs) About Home Insulation

1. What R-value do I need for my attic?

The recommended R-value for attic insulation depends on your climate zone and whether the attic is finished or unfinished:

  • Cold Climates (Zones 5–8, Northern U.S.): R-49 to R-60 for unfinished attics; R-38 to R-49 for finished attics.
  • Moderate Climates (Zones 3–4, Central U.S.): R-38 to R-49.
  • Warm Climates (Zones 1–2, Southern U.S.): R-30 to R-38.
  • Check the U.S. Department of Energy’s climate zone map for your specific zone: for example, a home in Minnesota (Zone 6) needs R-49–R-60, while one in Florida (Zone 2) may only need R-30–R-38.
  • Note: Ensure proper air sealing and ventilation to maximize insulation performance. Adding insulation beyond the recommended R-value may have diminishing returns.

2. How long does insulation last?

Insulation lifespan varies by material, installation quality, and environmental conditions:

  • Fiberglass: 20–50 years or more, if undisturbed and kept dry; may settle or degrade if exposed to moisture.
  • Cellulose: 20–30 years; can settle 10–20% over time, reducing effectiveness, and may degrade if wet.
  • Foam Board: 50+ years; durable if protected from UV light and physical damage.
  • Spray Foam: 50+ years; highly durable, especially closed-cell, but may degrade if exposed to prolonged moisture or UV.
  • Mineral Wool: 50+ years; resistant to fire and moisture, maintaining performance if properly installed.
  • Radiant Barrier: 20–50 years; lasts as long as the foil or coating remains intact.
  • Factors Affecting Lifespan: Poor installation, moisture exposure, pest damage, or physical disturbance can reduce longevity. Regular inspections (every 5–10 years) help ensure performance.

3. Is spray foam better than fiberglass?

Whether spray foam is better than fiberglass depends on your needs, budget, and project:

  • Spray Foam Advantages:
    • Higher R-value per inch (open-cell: R-3.5–3.6; closed-cell: R-6.0–7.0 vs. fiberglass: R-2.9–4.3).
    • Superior air-sealing, reducing drafts and energy loss.
    • Closed-cell foam adds structural strength and moisture resistance, ideal for basements or humid areas.
    • Expands to fill gaps, making it effective for irregular spaces.
  • Spray Foam Disadvantages:
    • Much more expensive ($1.00–$4.50 per sq. ft. vs. fiberglass $0.30–$2.50).
    • Requires professional installation.
    • Less eco-friendly due to chemical off-gassing and high embodied energy.
  • Fiberglass Advantages:
    • Affordable and widely available.
    • DIY-friendly (batts/rolls).
    • Non-combustible and recyclable.
  • Fiberglass Disadvantages:
    • Lower R-value, requiring thicker layers.
    • Can lose effectiveness if compressed or wet.
    • Less effective at air-sealing unless paired with additional sealing measures.
  • Verdict:
    • Spray foam is better for air-tightness, high R-value in tight spaces, or moisture-prone areas. Fiberglass is better for budget-conscious projects or easily accessible areas like attics. Combine both for cost-effective performance (e.g. fiberglass for bulk insulation, spray foam for sealing gaps).

4. What is the most eco-friendly insulation?

Cellulose is generally considered the most eco-friendly insulation due to:

  • High Recycled Content: Made from 80–90% recycled paper (e.g. newsprint), reducing landfill waste.
  • Low Embodied Energy: Requires less energy to produce compared to spray foam or foam board.
  • Biodegradability: Decomposes naturally if removed (though treated for fire/pest resistance).
  • Performance: Offers good R-value (R-3.1–3.8 per inch) and soundproofing.
  • Other Eco-Friendly Options:
    • Mineral Wool: Often contains 70–90% recycled slag or basalt; low environmental impact but higher production energy than cellulose.
    • Sheep’s Wool: Renewable, biodegradable, and chemical-free, but expensive and less common (R-3.5–3.8 per inch).
    • Cotton/Denim: Made from recycled clothing (e.g. denim scraps), chemical-free, but costly and less widely available (R-3.0–3.7 per inch).
  • Less Eco-Friendly Options:
    • Spray Foam and Foam Board: High embodied energy, non-recyclable, and potential chemical off-gassing.
    • Fiberglass: Moderate eco-impact; uses some recycled glass but requires significant energy to produce.
  • Considerations:
    • Choose certified products (e.g. GreenGuard or Energy Star) and ensure proper installation to maximize energy savings, which enhances environmental benefits

 

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