Insulation is a key component of sustainable building design. A well insulated home reduces energy bills by keeping warm in the winter and cool in the summer, and this in turn cuts down carbon emissions linked to global climate change.

In terms of energy efficiency, investing in high levels of insulation materials for your home is more cost-effective than investing in expensive heating technologies. It is worth taking the time to choose the right materials in the context of whole building design.

Insulation materials work by resisting heat flow, measured by an R-value (the higher the R-value, the greater the insulation). This R-value varies according to material type, density and thickness, and is affected by thermal bridging, unwanted heat flow that occurs at joists, studs and rafter beams.


Natural Insulation

Natural insulation has a unique combination of key characteristics which helps to create a healthier, comfortable, energy efficient, durable construction.

Natural insulation allows buildings to breathe by regulating humidity through their absorbent properties, and reducing problems of condensation. This keeps the indoor environment comfortable and protects any timber structures from rot.   When compared to synthetic materials, natural insulation products are generally far better materials in terms of performance and durability.  

Natural insulation systems vary from wood fibre mats, hemp, sheep’s wool, wood-fibre soft-boards and cellulose/recycled paper products.

Many natural insulation materials not only reduce heat loss and CO2 in buildings, but also my absorb CO2 while being harvested, such as hemp or wood-fibre.   It has been proven that for every cubic metre of Thermo Hemp natural insulation produced, at least 13kg of CO2 if absorbed. 

Living health, durability, and comfort are now considered just as critical as thermal performance. It is for this reason that natural insulation has now moved from being a fringe insulation material to the mainstream in Irish and British homes.

Constructions which are energy efficient, durable, healthy, ecological and sustainable in every sense of the word should be designed with some form of natural insulation, the benefits of which are not only in the money we save, but in the environment in which we live, particularly as it is estimated that we spend up to 90% of our lives in buildings.

Whether natural or man made insulation is used in buildings, the air-tightness of the building envelope is integral for building performance - please see our air-tightness and wind-tightness area on the website for more information.


With such a range of insulation available,

it makes sense to install natural insulation.  Natural insulation

  • They are low impact
  • Made from renewable, organic resources
  • Have low embodied energy.
  • They can be reused and recycled,
  • They are fully biodegradable.
  • They are non-toxic and allergen-free
  • They can be safely handled and installed.


Thermafleece Eco Roll

Wool is capable of absorbing more moisture than any other natural fibre due its high fibre saturation point.  This means that wool can absorb nearly 40% of its own weight in moisture and still feel dry to the touch.  Because wool binds moisture rather than just absorbing it, the performance of Thermafleece insulation does not vary significantly as humidity levels in the building change.  This can help contribute towards a more comfortable and healthy indoor environment.

The complex protein structure of the wool fibre enables it to absorb and safely fix many airborne substances that can be harmful in the indoor environment, including formaldehyde, which is released from many fabricated materials in the home.  Amongst natural fibres, this is a property that is unique to proteins such as wool.

Because THERMAFLEECE is made from the same materials commonly used in clothing and fabrics, it can be safely recycled at the end of its life into a variety of uses.

THERMAFLEECE EcoRoll is a wool based insulation that is compress packed and ideal for quick and easy installation. THERMAFLEECE EcoRoll contains 75% wool blended with 15% recycled polyester and 10% polyester binder.

THERMAFLEECE EcoRoll’s convenient compressed form reduces transport impacts by more than 50% compared to other natural insulations. Once unpacked, it regains its original thickness to provide excellent thermal and acoustic insulation.



Like all THERMAFLEECE wool products, it is long-lasting, safe to handle and can contribute to a healthier indoor environment by acting as a moisture buffer and absorbing indoor pollutants such as formaldehyde in the building fabric.

  • Sustainable
  • Contains British Wool
  • Made in the UK
  • Manufactured to ISO 9001 & 14001
  • Width (mm): 370, 570
  • Thickness (mm): 50, 75, 100, 140
  • Thermal conductivity: 0.039 W/mK

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Thermo-Hemp is a natural insulation material manufactured from hemp by Hock in Bavaria, Germany.
Hemp grows up to a height of nearly 4 metres within a period of 100-120 days. Because the plants shade the soil, no chemical protection or toxic additives are required for hemp cultivation. As well as having low embodied energy during manufacture, hemp is carbon negative as it locks in carbon during its growth.

Hemp is one of the oldest cultivated plants on earth, hemp is not only used as an excellent insulating material, but also for clothing, paper, oil, fuel, food and other construction materials.

With a thermal conductivity of 0.038W/(m.k), a density of 38kg/M3 and thicknesses ranging from 40mm to 200mm, Thermo-Hemp is the perfect solution for wall, floor and roof applications in both and new and old buildings.

  • Heathier for you - made from natural hemp plant fibres grown without any chemicals or toxic additives. Thermo-Hemp is totally safe and easy for you to install.
  • Healthier for your home - its hygroscopic properties hemp regulate humdity offsetting condensation risk. What’s more it’s naturally resistant to mould growth and insect attack and has outstanding fire resistance.
  • Healthier for the environment - as well as having low embodied energy during manufacture, hemp is carbon negative as it locks in carbon during it’s growth.
Thickness (mm) 40/50/60/80/100/140/200
Length x width (mm) 580 x 1200/375 x 1200
Bulk density (kg/m3) 38
Components 82-85% hemp fibres, 10-15% bi-component fibres, 3-5% soda for fireproofing
Thermal conductivity D(W/mK) 0.038
Water Vapour Diffusion Resistance Coefficient 1 - 2.
Length Related Flow Resistance 6.0 kPa.s/m2.
Maximum Processing Temperature 120C.
Sensitivity to mould fungus (accoridng to EN 1SO 856): No mould fungus growth identifiable.
production process Dry
European Technical Approval AbZ No. Z23.16-1577
Specific Thermal Capacity 1600 J/(kg.K).
Usage Interior only.









For over 75 years, the Black Forest family-owned and operated company GUTEX Holzfaserplattenwerk GmbH + Co KG has produced insulating board from wood at its plant in Waldshut-Tiengen, Germany. GUTEX is an established brand name for fibreboard manufactured from wood.

The raw material for all GUTEX insulation boards comes solely from wood that is harvested and grown using sustained forestry management practices. It is obtained as chips and shavings from sawmills located near the GUTEX plant, another feature that makes the products even more environment-friendly.

GUTEX insulation is suitable for both new buildings and the renovation of older buildings. It may be used in thermal insulation composite systems for building facades or as wall insulation for vented facades as well as over-rafter and between-rafter insulation to complement already existing above-rafter sarking.

It provides highly suitable insulation of ceilings between storeys and insulation of the inner sides of exterior walls. GUTEX insulation products are also ideal for use as impact soundproofing of floors, acoustic underlay for wood floors and insulation of cavities in which plumbing and electrical lines are installed.

Technical advantages:

GUTEX insulation boards possess all the virtues you would expect from an ecological modern insulation material.

GUTEX produces its soft boards using the most modern environment-friendly manufacturing technique (dry process) available.

GUTEX’s market and quality leadership are largely attributable to its ability to produce single-ply insulation boards in up to 240 mm thickness, eliminating the need for multiple layers of lamination.

In addition, the boards have an extremely homogeneous bulk density and exceptional compressive strength.

Ecological advantages:

The raw material for all GUTEX insulation boards, chiefly fir and spruce, comes from wood that is harvested and grown near the plant using sustained forestry management practices.

Certificates, such as thenatureplus® seal of quality attest to the boards’ biological safeness.

Advantages for buildings:

GUTEX insulation boards deliver excellent protection against the cold in winter and the heat in summer. In fact, wood has the highest volumetric heat storage capacity of all insulation materials!

Moreover, wood fibreboards are diffusion permeable and regulate moisture, producing a healthy indoor environment.

Thanks to their high volumetric storage capacity and open fibre structure, the boards are ideal for soundproofing applications.

Fire resistance rated building constructions up to F90-B are possible with GUTEX wood fibreboards. And should they burn, GUTEX fibreboards do not emit toxic fumes!

What do Gutex wood fibreboards contain?

Why are Gutex wood fibreboards considered ecological products?

First, wood chips, which are the raw materials used to make GUTEX softwood fibreboards, are by-products of the wood making process.

Second, the sawmills from which GUTEX obtains its chips are all located near the plant, translating into less pollution and consumption of fuel thanks to reduced transport distances.

Thirdly, all the products are manufactured from wood obtained through sustained forestry practices.

In addition, GUTEX wood fibreboards are biodegradable and can be recycled, provided they have not been treated with wood preservatives.

Finally, when a tree burns or decomposes, it releases the same amount of CO² into the environment that it had assimilated during its lifespan. GUTEX boards are manufactured from wood chips and shavings and therefore do not increase the level of CO² gas in the atmosphere!

All GUTEX wood fibre insulation products bear the natureplus® mark of quality. The new dry process employs an innovative environment-friendly technology that uses 40% less energy per manufactured metric tonne than the conventional wet technique!

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