Eco Friendly Insulation

Since the dawn of construction, people have been finding creative ways to insulate their buildings. During today’s green revolution, eco-friendly insulation materials and methods are quickly gaining popularity, each more inventive than the next. 

In this complete guide to eco-friendly insulation, we will examine some of the most practical modern materials that can work in many different instances and applications. After outlining how to choose the best eco-friendly insulation for your building, we will showcase five interesting examples of environmentally-conscious insulation from around the world.   

What is Eco-Friendly Insulation? 

Eco-friendly insulation is a large, catch-all term for a number of different natural and manmade materials used to insulate homes and buildings. In order to be considered eco-friendly, insulation materials generally meet one or more of the following criteria:

  • Coming from natural or recycled materials
  • Containing no toxic chemicals
  • And producing limited greenhouse gas emissions in manufacturing

Just as with any other material, the goal of eco-friendly insulation is simply to insulate a building from outside conditions. High-quality insulation is able to keep a home warm in the winter and cool in the summer by halting airflow in its tracks. When it’s implemented correctly, eco-friendly insulation can dramatically reduce the costs of heating and cooling a home with a boiler, air conditioning unit, or other active temperature control appliance

Some of the most common eco-friendly insulation materials include:

  • Cellulose 
  • Cotton / Denim 
  • Sheep’s Wool 
  • Mineral Stone Wool 
  • Hemp 
  • Straw 
  • And more 

Why use Eco-Friendly Insulation?

As every building in the world can benefit from some level of insulation, an environmental shift in the industry has global, snowballing consequences. Eco-friendly insulation is designed to suit a more sustainable world for the health of our planet and its inhabitants. 

In addition to the atmospheric carbon offsets, eco-friendly is also installed with the health and safety of the end-user in mind. While off-gassing from synthetic materials has driven the market away from asbestos-based insulation, eco-friendly materials are quickly becoming cheaper and more readily available in buildings all over the world. 

Be Prepared for Higher Costs with Eco-Friendly Insulation

Even if your head is in the right place, several eco-friendly insulation options come with a higher price tag.

The price of high-quality materials like denim and sheep’s wool insulation is driven up by the cost to treat, shape, and export. Of course, shipping costs on eco-friendly insulation materials are inherently lower, as oftentimes, green consumers are more likely to source local products.  

How to Pick the Right Eco-Friendly Insulation

Around the world, the best insulation for a given project is going to vary heavily depending on local conditions. While there is no “right answer” for the absolute greatest eco-friendly insulation, there are a few common attributes of today’s environmentally friendly insulation materials that can be used to narrow down your choice.     


First, the most important thing to consider when choosing eco-friendly insulation is the material’s R-value. If you are unfamiliar with this rating, an R-value represents an insulation material’s ability to retain heat on a scale from 1 to 60. Here, the greater the R-value, the better an insulator can retain heating and cool air within a building. 

Of course, not every building needs the highest R-value possible. Instead, the approximate R-value necessary to efficiently insulate a building is heavily dependent on the climate of the area. In the contiguous United States, there are 7 climate zones as illustrated in the map below from  

In warm weather climate zones such as 1, 2, and 3, insulations with R-values around 30 can generally be used to fully insulate a home’s walls, attics, and floors. For zones 4, 5, and 6, R-values of 40, 50, and 60 are more likely to perform better against harsher weather conditions. Wherever you live, we recommend speaking with local contractors before ultimately deciding on what R-value insulator you choose for your building.   


Second, it is impossible to ignore price as one of the most important driving factors with your insulation choice. Although we would all like to save the world, some high-quality materials may not be affordable when it comes time to protect your building against the outside elements. 

With that being said, the best insulation helps keep costs low overtime with lowered energy expenses. Knowing this, we always recommend erring on the side of caution by overpaying for top-notch insulation now, and not having to worry about the costly consequences of cheap insulating materials later. 

To calculate the total cost of your insulation, there are a few factors to consider. If you are utilizing a full-service contractor, they will likely provide you with a total estimated project cost, which can sometimes be broken down into different categories such as:

  • labor
  • materials
  • transportation
  • and overhead costs

While some of these expenses can be mitigated by doing the insulation yourself, it is generally easier and less stressful to hire someone for the job. 

Local availability

Lastly, choosing the right environmentally friendly insulation is always going to be limited by the local availability of the materials. When tallying up potential emissions, far-reaching transportation costs can quickly add to a project’s total greenhouse emissions when considering supply chain emissions from cars, trucks, and other vehicles. Although nationally sourcing the cheapest material possible may save you a few bucks upfront, the most environmentally friendly insulation materials are generally those that are readily available (or can be created) nearby.   

Eco-Friendly Insulation Materials

Certainly, there is no one-size-fits-all eco-friendly insulation solution. Every building and application is different and therefore certain insulation materials may lend themselves as better choices in different scenarios. 

While evaluating the R-value, price, and availability, every eco-friendly insulation material has its own distinct set of pros and cons. Below, we will explore some of the most commonly used eco-friendly insulation materials in detail. 

Cellulose Insulation

To start, cellulose is one of the most widely available and commonly used forms of eco-friendly insulation. Commercially available cellulose insulation may be wood or paper-based and is often manufactured with up to 85% recycled material. It is also produced regionally all around the world, which dramatically lowers its shipping costs and supply chain emissions footprint.   

When it is manufactured, cellulose typically only requires the use of electric mechanics, which can also come from green energy sources. Altogether, these factors combine to give cellulose insulation the lowest embodied energy rating amongst popular modern materials.  

Cellulose is typically blown into a structure’s walls, attics, and floors with hoses and other specialty equipment. Once installed, cellulose is a great insulator for noise and retaining internal temperatures. One of the largest drawbacks of cellulose insulation is its relatively low r-value compared to its weight. Beyond this, treated cellulose materials may be responsible for mild off-gassing as well as potential slumping or mold growth.      

Denim / Cotton Insulation

Just like your blue jeans, denim is another natural fiber that can be used as an environmentally friendly insulation material for homes and businesses. Denim insulation is typically produced by recycling denim clothing and is often combined and blended with other recycled garment materials like cotton. 

To install denim insulation, most home builders typically fill the walls with large pieces known as batts. For harder to reach areas, it is also common to blow in a denim blend loose-fill. Compared to rougher materials like fiberglass, denim insulation is much easier to install for DIY projects. 

Denim has many advantages that can provide long-term, toxin-free insulation for a building. As many people know, global textile waste is very high, and denim insulation is a great, sustainable way to create useful products instead of adding spent materials to landfills. Unfortunately, denim insulation is quite costly, and large shipments may incur additional large pre-installation expenses.  

Sheep’s Wool Insulation

Sheep’s wool is another mildly expensive, yet incredible high performing insulation material that is the perfect compliment to sustainable homes and other eco-friendly construction. While it is not taken directly from the shears, sheep’s wool insulation is typically made from scrapped and recycled pieces from manufacturing carpets and other wool products.  

Compared to most other insulation type’s sheep’s wool insulation has the highest R-value, pound for pound. The unique material naturally stores heat, captures VOCs, and is capable of absorbing up to 40% of its own weight in condensation. Sheep’s wool insulation is long-lasting, with an expected lifespan of over 100 years.

Mineral Stone Wool Insulation

Next, mineral stone wool is a popular insulation material that can often be referred to simply as mineral, stone, rock, or slag wool. Mineral wool is created by drawing or spinning molten mineral and rock materials into a man-made vitreous fiber (MMVF).

Slag wool has been used in buildings since the mid-1800s, with many forms of manufacturing and materials used. Some old mineral wool may contain harmful chemicals such as asbestos, however, this has become increasingly rare in modern applications. Mineral wool is a great insulator but scores fewer environmental points than most other materials in this article. 

Hemp Insulation 

Continuing with naturally fibrous materials, hemp insulation is growing in popularity amongst eco-friendly builders. Hemp typically delivers higher R-values than other natural materials like wool and denim but can be a bit more expensive to attain and install. As a fast-growing and resilient crop, hemp is a very sustainable solution for long term material production. 

Until recently, industrial hemp was not allowed to be grown in the United States due to its association with marijuana, however, its newfound legality has quickly made its way into many different industries. Hemp insulation is generally sold in batts, which combine mostly hemp with about 10% other materials like polyester fiber. 

Straw Bale Insulation 

To the surprise of many, straw is actually a great eco-friendly material that can be used in a variety of insulation installations. Straw can be treated in a few different ways, with most modern applications compressing the materials into structurally insulated panels (SIPs) or other easy to transport materials.

In many instances, however, straw bales are used not only for insulation but also as part of the structural integrity in many unique building projects. We will expand on this idea in our “real-life examples” section below. 

Real-Life Examples of Eco-Friendly Insulation

In the United States and abroad, eco-friendly insulation materials have been gaining speed in the marketplace over the last few decades. As green materials are clearly now more than just a trend, a trip to the home improvement store or specialty shop is likely to yield at least one or two eco-friendly materials to choose from. Today, it is not difficult for home builders to get their hands on:

  • Blown-in cellulose insulation 
  • A variety of wool and denim (in rolls or sheets)
  • And more

Aside from immediate commercial products, creativity, innovation, and green initiatives continue to deliver new eco-friendly insulation solutions. Below, we will showcase some interesting real-life examples of eco-friendly insulation from around the world. 

Image source:

The IronStraw Public Library in Mattawa, Washington

First, we invite you to take a look at the building above. Looks like a pretty normal structure, right? Well, believe it or not, the image above displays the IronStraw Public Library in Mattawa, Washington, which is the first “strawbale public library in the United States.” Only a thick layer of stucco and some basic wood framing separate this building from being identical to a straw house, such as in Three Little Pigs. 

Not only are straw bales used to insulate this library, but the straw is also critical to the very structural integrity of the building. The Ironstraw Group takes advantage of the strong, lightweight straw bales which are easy to transport and stack. The wide walls of the building make it earthquake-safe and the thick insulation help reduce heating and cooling costs. 

This project is quite eco-friendly because straw is readily available in rural areas of the United States, such as Mattawa. The annual crop gives farmers an additional source of income, and gives homeowners and businesses security knowing that the insulation in their building is made of completely natural sources. 

Image source:

Sheep Wool in Nomadic Mongolian Yurts

Next, we would like to take a trip through time to showcase the true inventiveness of eco-friendly insulation. For centuries, nomadic residents of modern-day Mongolia have been using sheep’s wool to stay warm all winter long. This is critical when you realize that this northern hemisphere country that reaches thirty below zero in the winter.

Sheep wool is one of the most popular textiles in Mongolia. It is readily available and used in many other applications like clothing and bedding. For insulation, the wool of a sheep is felted and woven into pads, which are then used to line the walls of a building. In the image above, you can see a common Mongolian yurt that is lined with a thick layer of sheep wool.

Famously, the nomadic nature of ancient and modern Mongolians requires ongoing movement and continuous migration. Here, sheep’s wool is lightweight and easily carried, making it perfect for insulating a structure that must be moved. Beyond this, the renewable and heavy insulating properties of sheep’s wool have made it common in Mongolia’s permanent structures of today just the same.       

Image source:

The Cellulose Insulation Manufacturers Association

What many people do not know is how readily available eco-friendly insulation is in most parts of the world today. For this reason, we would like to showcase the Cellulose Insulation Manufacturers Association (CIMA), as a national organization supporting the growth of the cellulose insulation industry. Funny enough, you can find their webpage at simply,

CIMA is a network of cellulose insulation manufacturers, contractors, enthusiasts, and more. The group makes it possible to find the most eco-friendly (and economical) cellulose insulation solution for new and existing buildings throughout the United States. By leveraging a network of partners, CIMA makes it easy to find local manufacturers and contractors to limit the overall carbon profile of the installation. 

In the image above, you can see a contractor blowing cellulose insulation into the floor of a building. It’s high R-value and flexible nature allow it to fully insulate floors in a quick and efficient manner. 

Europe’s Radical Hemp Concrete 

Jumping to the other side of the pond, we would lastly like to feature an exciting building trend that has been developing in Europe: hemp concrete. As pictured above, hemp concrete looks just like it sounds, built to resemble ordinary concrete blocks with natural materials. 

The walls in this particular building are made with “hemp clay bricks” which can also be called “hempcrete” or “hemp-lime” The technology that has been mainly in the works for the last 25 years began in Europe and has slowly crept into other parts of the world. Hemp concrete is typically blended with a few other natural, renewable materials including straw and pine. With hyper dense manufacturing, hemp bricks are often lighter and stronger than clay and steel.  


Before we wrap up, here are a few of the most commonly asked questions about eco-friendly insulation. 

What is the most eco-friendly insulating material?

Today, cellulose is widely considered to be one of the most eco-friendly insulating materials in the world. It is made of recycled materials that can be found in almost every major civilization. If cellulose is not readily available in your area, other local materials may be more eco-friendly overall. 

What is the least toxic insulation material?

Any insulator that does not emit CFCs or contain formaldehyde can be considered non-toxic. In most cases, natural and untreated materials like straw or hemp can be called the “least toxic” insulation material.  

What is energy efficient insulation? 

Although the insulation itself is not energy efficient, the term “energy-efficient insulation” refers to an insulator’s ability to improve a building’s energy efficiency. Good insulation helps trap in heat and cooling for optimal interior temperatures with minimal energy usage. 


To sum things up, there is no limit to the possibilities of eco-friendly insulation. With many great companies and innovators continuously pushing practical and ethical solutions, eco-friendly insulation is a very achievable goal for today’s homes and businesses throughout the world.