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Insulation: Choosing the Best Insulation for Your Home

By Tobias RobertsRise Writer
Sep 11, 2019

Insulation is a staple of home construction in North America. The problem? One recent study found that upwards of 90 percent of existing homes in the United States are under-insulated. Heating and cooling make up between 35 and 40 percent of total energy use in North American homes. Therefore, improving your insulation is a simple and straightforward way to improve your home's energy efficiency and thermal performance significantly. In this guide, we offer a complete rundown of the pros and cons of the most common types of insulation used in American homes.

Table of Contents

  1. What to Consider Before Installing Insulation in Your Home ,Pros and Cons of Different Insulation Options 
  2. What Is Fiberglass Insulation?
  3. What Are the Pros of Fiberglass Insulation?
  4. What Are the Cons of Fiberglass Insulation?
  5. What Is Cellulose Insulation?
  6. What Are the Pros of Cellulose Insulation?
  7. What Are the Cons of Cellulose Insulation?
  8. What Is Spray Foam Insulation?
  9. What Are the Pros of Spray Foam Insulation?
  10. What Are the Cons of Spray Foam Insulation?
  11. What Is Mineral Wool Insulation?
  12. What Are the Pros of Mineral Wool Insulation?
  13. What Are the Cons of Mineral Wool Insulation?
  14. What Is Natural Fiber Insulation?
  15. What Are the Pros Natural Fiber Insulation
  16. What Are the Cons Natural Fiber Insulation?

What to Consider Before Installing Insulation in Your Home 

The typical American family spends upwards of $2,000 a year on their home energy bills. You can lower your heating and cooling costs by installing a smart thermostat or investing in a more energy-efficient heat pump. But an under-insulated home will always run the risk of suffering from significant heat gains and losses. Thus, one of the first considerations for an energy-efficient home renovation is the amount of money you currently spend on energy bills.

In some cases, older homes with leaky building envelopes and poor insulation will see dramatic savings through improved insulation. These types of homes will typically see an attractive payback on any insulation investments. If your energy bills have become a significant household expense, local lenders' energy efficiency financing might make economic sense and begin to save you money immediately.

Other important considerations when focusing on insulation options include the following:

Healthy Indoor Air Quality

In today's highly competitive construction landscape, cost drives most building material decisions. The easiest way for a construction team to lower overall costs is through the use of cheaper materials. Not only has this practice sacrificed home performance, but it has also led to a series of adverse health and environmental impacts.

Optimum R-Values

Homeowners will want to determine the amount of insulation that is optimum for the specific climate. Insulation is rated by "R-Values," meaning resistance to heat flow. The higher the R-value, the greater the insulating power of the insulation product. The optimum R-Value for your insulation requirements will depend on several factors. These include weather, the structural condition of your home, the construction style, and how you heat and cool your home. To get a general idea of the insulation requirements for your home, the U.S. Department of Energy offers a climate zone map by countyThis insulation company provides a step-by-step instructional to help you determine the minimum insulation requirement for your home.

Embodied Energy Footprint

The Australian government's Guide to Environmentally Sustainable Homes explains embodied energy as "the energy consumed by all of the processes associated with the production of a building." These include the mining and processing of natural resources, manufacturing of the product, transportation, and product delivery. While all insulation options will increase your home's energy efficiency performance, these efficiency gains need to be weighed against the emissions associated with the manufacture of the product itself. One recent analysis found that synthetic insulators like foam and fiberglass have the worst balance sheet. Mineral wools are slightly negative. But natural fibers, like wool and cellulose, have a positive climate impact.

Pros and Cons of Different Insulation Options 

While blanket insulation options (batts and rolls) are the most common insulation types on the market, there are several types of innovative insulation options available to homeowners today.

fiberglass batt insulation
Photo Credit: Anderson Insulation

What Is Fiberglass Insulation?

Fiberglass insulation is a common insulation option made from glass and sand spun into a fine fiber with a bonding agent. Fiberglass insulation is available in both batts and rolls and available in medium and high density. It's lower cost and high R-value makes it one of the most commonly used insulation materials.

What Are the Pros of Fiberglass Insulation?

Fiberglass comes in various forms, including blanket (batts and rolls), loose-fill insulation, and rigid boards and duct insulation. Homeowners can use fiberglass insulation for almost every home and room, and the high-density batts can offer high R-values. Most manufacturers utilize up to 60 percent recycled glass in their finished product.

What Are the Cons of Fiberglass Insulation?

Fiberglass insulation is usually bonded together with formaldehyde, which emits dangerous particulate matter (VOC) into one's home. This is particularly harmful to homeowners who have a forced-air heating or cooling system. This product is seldom recyclable and ends up in municipal landfills. It also requires gloves to install, as the small glass particles can be itchy and painful.

cellulose insulation
Photo Credit: Eco insulation®

What Is Cellulose Insulation?

Almost all cellulose insulation is made from recycled newspapers. The cellulose is broken into small pieces and then fiberized. The final product can be packed tightly into building cavities to inhibit airflow substantially. Today, almost all manufacturers add borate to ensure fire and insect resistance.

What Are the Pros of Cellulose Insulation?

Most cellulose insulation is made from up to 85 percent recycled material, which dramatically reduces this type of insulation's carbon footprint. This bio-based insulation option can be blown into existing walls, reducing installation costs for home renovation projects.

What Are the Cons of Cellulose Insulation?

Cellulose insulation is at serious risk for moisture damage. Even a small amount of moisture can impact the resistance value while breaking down the paper fibers. As bio-based insulation, this is where cellulose falls short and can lead to mold growth.

spray foam insulation
Photo Credit: Spray Right Foam Insulation

What Is Spray Foam Insulation?

Spray foam is a chemical-based insulation product that expands up to thirty to sixty times its size from a mixing reaction caused during the spraying process. There are several types of foam insulation products, including polyisocyanurate, polystyrene, and polyurethane. When sprayed, they act as insulation and air barrier material that seals walls, floors, and ceiling cavities against air movement. Closed-cell spray foam is typically more expensive than open-cell spray foam. All foam types need to be mixed and sprayed on-site.

What Are the Pros of Spray Foam Insulation?

Unlike other insulation materials, spray foam insulation can fill cracks, gaps, and crevices on installation, thus improving your home's building envelope. It typically has the highest R-Value per square foot and can be installed over virtually any surface.

What Are the Cons of Spray Foam Insulation?

As a petrochemical product, spray foam insulation has an extremely high embodied energy footprint. It also emits harmful chemicals that can negatively affect the environment. One recent report by the EEFA finds that chemical foams might include dangerous toxins such as formaldehyde-based binders, halogenated flame-retardants, orthophthalates, isocyanates, and organotins. Workers installing spray foam insulation must wear protective masks at all times. 

rockwool insulation
Rockwool insulation. Photo Credit: Pheasant Hill Homes

What Is Mineral Wool Insulation?

Mineral wool insulation can be made from rock wool that consists of natural minerals like basalt or diabase. It can also be slag wool, made from blast furnace slag, or the waste matter that forms on the surface of molten metal.

What Are the Pros of Mineral Wool Insulation?

On average, mineral wool is made from 75 percent post-industrial recycled content, reducing its carbon footprint. Because it is made from metals, it doesn't require any chemical flame retardants and can be sold as either batts, rolls, or loose-fill insulation.

What Are the Cons of Mineral Wool Insulation?

Mineral wool insulation can release tiny metal slivers that can become lodged in the skin and are small enough to be inhaled. While this danger is usually most serious during installation, the inhaled slivers of mineral wool can irritate the alveoli and lead to lung disease.

wool insulation
Photo Credit: Havelock Wool

What Is Natural Fiber Insulation?

Many natural products can be used for home insulation, including:

These products are typically treated with borate or other chemicals or minerals to protect from fire, water, and insect damage.

What Are the Pros Natural Fiber Insulation

Many of these natural materials can be considered to be carbon positive, as they will absorb CO2 from the atmosphere as they grow. They do not off-gas will not contribute to VOCs in your home. They are all renewable materials and are biodegradable when disposed of. Cotton and wool are also excellent noise barriers. Wool and cotton insulation is easily handled and does not require protective gear for installation.

What Are the Cons Natural Fiber Insulation?

Moisture, fire, and insect damage can be a concern, especially if the product is untreated. These products can be significantly more expensive, and it can be a challenge to find installers who know how to insulate with natural fiber materials.

When considering which type of insulation is the most "sustainable," there are many factors: the R-value, embodied energy, level of toxicity, ease of installation, performance when wet, fire resistance, the lifecycle of the product, etc. Additional considerations include cost, of course, as well as ease of installation. There is no one perfect solution; there are always tradeoffs. But a well-insulated home is a more sustainable home. So, figure out which traits you value most and choose one that meets your needs.

Disclaimer: This article does not constitute a product endorsement however Rise does reserve the right to recommend relevant products based on the articles content to provide a more comprehensive experience for the reader.Last Modified: 2021-07-10T05:33:50+0000
Tobias Roberts

Article by:

Tobias Roberts

Tobias runs an agroecology farm and a natural building collective in the mountains of El Salvador. He specializes in earthen construction methods and uses permaculture design methods to integrate structures into the sustainability of the landscape.