If you are someone taking on the challenge to build or plan your own sustainable home, you may want to re-consider what type of insulation material you are using to wrap around the walls, floors, and roof.

Just because insulation drives up your home’s energy efficiency, it doesn't immediately make it sustainable – in some cases the choice of material itself can often be toxic for our environment and health.
Introducing Natural Fibre Insulation - an eco-alternative which is becoming increasingly more popular in the world of sustainable construction!
wood chips
Natural Fibre Insulation - For example wood fibre insulation is made from sustainably sourced timber which is ground with water to form a pulp. This is then heated and compressed into blocks or boards.



The Importance of Insulation in Energy Efficient Homes

Before we dive into the details of what NFI is and its benefits, we first need to address the importance of insulation in any home.

Without proper insulation, the principles of thermodynamics will leave us icy cold during freezing winters, cause frequent condensation leading to mould, damp, and plethora of structural issues!

That’s where insulation comes in handy – to help prevent or minimise the transfer of heat entering and leaving the home to contribute to an optimal internal temperature.
Insulation alone, whether green or not, helps to significantly enhance a home’s energy efficiency. Statistics from the U.K. Department of Energy and Climate Change show that more than 78% of a household’s energy consumption is due to heating requirements – something that can be significantly reduced with the help of better insulated homes.

What is Natural Fibre Insulation?

Insulation materials for the home vary drastically, ranging from different types like blankets, foam boards, concrete blocks, and more for different purposes.
Natural Fibre Insulation is an overarching term used to describe the many types of insulating material available in the market that are derived from natural materials like hemp and wool instead of synthetic materials like polyethylene, polyurethane, liquid foam, etc.
Hempcrete construction hemp walls blocks
Photo courtesy of UK Hempcrete. Copyright UK Hempcrete
A “composite material made from wet-mixing hemp shiv with a lime binder, Hempcrete provides a natural, vapour-permeable, airtight insulation material which also has great thermal mass, giving it a uniquely effective thermal performance. It can be used in wet-cast form or as pre-cast hempcrete blocks (as illustrated above).” UK Hempcrete



Why Choose Natural Fibre Insulation: 7 Benefits Compared to Synthetic Alternatives

Wondering why you should opt for natural fibre insulation instead of synthetic materials? Here are 7 simple reasons to consider:


Thermal Performance

There is a common misconception that modern synthetic materials are the most capable in attaining high levels of energy efficiency.

But this is false. NFI materials are incredibly efficient at providing the same levels of energy efficiency (albeit requiring greater thickness). In fact, most natural materials can provide similar or even exceed insulation factors (R-values) as their synthetic counterparts.
And because of the high density of the natural materials and increased thickness, NFIs help to provide more thermal mass, helping to control heat loss and gain much better than synthetic materials.
So overall, NFI materials have a clear edge. Not only is the material more sustainable, but they can meet all of your high-performance demands.



Safe & Sustainable

This is a no-brainer. Compared to synthetic materials like polystyrene, the reduced environmental impact of manufacturing natural materials is clear to all.

Not only is it a renewable resource, but it also has the benefit of being carbon sequestering – meaning that it helps to trap and store carbon (in the form of carbon dioxide during growth and locking it in while in use) to reduce greenhouse gas emissions.

Increasingly, more natural insulation materials are making use of recycled waste fibres or lower value fibres, significantly cutting down on the overall carbon footprint.
And last but not least, natural materials are also not harmful to health since they are mostly animal, plant, or mineral-based and are not expected to cause irritation or require any special precautions for installation.
sustainable loft insulation
Photo courtesy of Thermafleece. Copyright Thermafleece.
Thermafleece CosyWool - A versatile roll insulation made from 75% British Wool and 25% recycled polyester. “Research shows that using 75% wool in combination with recycled fibres outperforms alternative products with a higher percentage of wool.” Thermafleece.

Air Quality

Did you know that choosing poor insulation materials can affect your health?

Indoor air quality can be compromised due to synthetic contaminates (VOC) and high levels of humidity leading to various respiratory problems including allergies and asthma, or worse, result in the deterioration of your health.

In contrast, NFIs are natural materials with very low levels of VOC and have very breathable properties due to the natural fibre network that helps to regulate the moisture levels within your home creating a much more comfortable internal climate and air quality.

In this aspect, NFI materials are a superior choice.



The durability of building materials is key to any building’s life span – and that is the case for housing insulation materials as well.
Think that just because NFIs are natural and do not contain any synthetic chemicals that they are less durable? That’s not quite the case.

Many natural insulation materials have incredible characteristics that make them extremely durable, some of which include:

  • Their breathability helps them to regulate moisture well – preventing over-accumulation of moisture which could cause structural damage through mould and mildew issues.

  • Depending on the specific choice of insulation material, some of them have varying degrees of natural resistance to rot, water, and fire – which is always a benefit for structural integrity.

And most importantly, they all do not damage the environment or give off toxins when reprocessed at end of life.


Photo courtesy of ISOCELL. Copyright ISOCELL
“ISOCELL is a natural thermal insulation made from cellulose fibres, which is created by recycling clean, unmixed newspaper. Coarsely fibered, mixed with mineral salts and ground in a mill, Isocell cellulose makes it rot-proof and fire-resistant.” ISOCELL



A new technology that is easy to use with optimal thermal performance, NFIs are clearly a staple in the modern construction industry.
With plenty of choices of NFIs to choose from, ranging from loose fill, boards, or blocks, homeowners are spoiled for choice when it comes to building material options that are compatible with their homes.


Worried about natural fibre insulation in the case of a fire? Well, don’t be. All NFI materials must be tested for fire safety and pass to be certified for use.

Not only that, compared to their synthetic counterparts, you can expect NFIs to emit a significantly lesser amount of toxic gases in the case of a fire too.

Acoustics Insulation

Here’s something you may not have thought of – natural fibre insulation also doubles up as amazing acoustic insulators thanks to their high density and irregular textures that help to absorb sound across the board.
Now, instead of forking out additional money and not to mention using up more resources for soundproofing your home from the noise in the neighbourhood, you get the benefits of soundproofing too when you opt for natural insulating materials. Win-win!
Sustainable insulation wood fibre
Photo courtesy of Back to Earth. Copyright Back to Earth.
Natural Wood Fibre Insulation which can be used for roof insulation, wall insulation and floor insulation.



NFIs: The Choice for Sustainability, Health & Comfort

Now having learnt about the various benefits of natural fibre insulation, would you not opt for NFIs too?

Your home is where you spend a significant amount of time (especially in this pandemic period), and NFIs can help you enjoy your stay at home in health, comfort, and most importantly, sustainably.


NFI Brands Perfect for Your Sustainable Home

Keen to incorporate NFIs for your home insulation? Here is a list of curated NFI suppliers to get you started.


 UdiRECO by Back to Earth

An eco-friendly wood fibre insulation board that is perfect for both internal and external use. And did we mention that it works even for uneven walls too?


Hemcrete Blocks by Natural Building Store

Lightweight, breathable, fireproof, with a reasonably high R-value of 2.4 -4.8 per inch, Hempcrete blocks are a great option for easy insulation of external walls and structures.


CosyWool By Thermafleece

Made from 75% sheep’s wool and 25% recycled fibres, CosyWool provides enhanced thermal performance over traditional wool-only products – a versatile insulation material that’s also great value for money.

Cellulose Insulation By Isocell

Isocell’s Cellulose Insulation material is made entirely from cellulose fibres extracted from recycled newspaper and mixed with minerals to make it rot-proof and fire-resistant and not to mention its special injection technique for seamless insulation all around.

Cellulose Insulation By Thermofloc

A light and fluffy loose cellulose insulation also made from recycled newspaper, Thermofloc offers yet another easy-to-install and cost-effective NFI material for homeowners to try out.


Sophia Major Profile Photo

Sophia Major, BA (Hons) MArch Architectural Designer & Certified Passivhaus designer

Founder of IGOLO. Our mission is to make sustainable home renovation & design more accessible and desirable for everyone.


September 18, 2021

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