Home > Construction Methods > Insulation Materials

Insulation Materials

By: Jennifer Gray - Updated: 7 Nov 2017 | comments*Discuss
Natural Insulation Conventional

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 are used in roofs, walls and floors. Solid wall structures such as stone, cob and adobe cannot be insulated, but they have good thermal mass to compensate. Timber frame homes need wall insulation in the form of batts (pre-cut sections that are designed to fit between stud walls), rolls or boards. Other types of construction such as brick or concrete insulate with spray foam, loose fill or rolls. It is far easier and cheaper to install insulation in the walls and floors of a new build home, than to retrofit an existing home. However, insulating roofs is easily achieved in any home using rolls or bags of loose fill.

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.

Conventional Insulation

Conventional insulation materials are made from petrochemicals and include: fibreglass, mineral wool, polystyrene, polyurethane foam, and multi-foils. These materials are widely used because not only are they inexpensive to buy and install, but there is an assumption from the building industry that their performance ability is higher than the natural alternatives. On the downside, almost all conventional insulation materials contain a wide range of chemical fire retardants, adhesives and other additives, and the embodied energy in the manufacturing process is very high.

Natural Insulation Materials

The green alternative to synthetic insulation is natural insulation. There are many different types available, including:

Sheep's Wool
This material usually needs to be treated with chemicals to prevent mite infestation and reduce fire risk, although some natural builders use it untreated with success. It has very low embodied energy (unless it is imported) and performs exceptionally well as an insulation material. Thermafleece is the most common commercial brand available.

Flax and Hemp
Natural plant fibres that are available in batts and rolls, and typically contain borates that act as a fungicide, insecticide and fire retardant. Potato starch is added to flax as a binder. Both materials have low embodied energy and are often combined in the same product. Examples include Isonat and Flax 100.

A recycled product made from newsprint and other cellulose fibre. It is one of the most favoured materials of natural builders because it can be blown into cavity walls, floors and roofs; used as a loose fill; and is also available in quilts, boards and batts. Like hemp and flax it contains borate as an additive. Products include: Warmcell and Ecocel.

Wood Fibre
Made from wood chips that have been compressed into boards or batts using water or natural resins as a binder. It has very low embodied energy and uses by-products from the forestry industry. Examples include: Pavatex, Thermowall and Homatherm.

Expanded Clay Aggregate
These are small fired clay pellets that expand at very high temperatures to become lightweight, porous and weight-bearing. They can be used in foundations as both an insulator and aggregate. They have excellent thermal insulation properties, but high embodied energy.

Insulating for a Better Environment

Natural insulation products have many advantages over conventional materials. They are low impact, made from renewable, organic resources and have low embodied energy. They can be reused and recycled, and are fully biodegradable. They are non-toxic, allergen-free and can be safely handled and installed. They also allow for a 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.

Unfortunately, natural insulation materials are currently up to four times more expensive than conventional materials, which can be prohibitive to builders, architects and developers. But the environmental and health benefits of natural insulation materials far outweigh their costs, and growing consumer demand combined with government regulation, and rising oil prices will inevitably drive prices down. Despite the high price, natural insulation is an energy-efficient, healthy and sustainable choice for a better indoor and outdoor environment.

You might also like...
Share Your Story, Join the Discussion or Seek Advice..
[Add a Comment]
Good Afternoon, My name is Mohammed, and I have been assigned a task from college to hypothetically build and new college building. we as a group are taking a sustainable approach, and I am just wondering what would be the best type of sustainable insulation to use, in terms of thermal attributes. Kind regards
flubber - 16-Mar-17 @ 1:19 PM
i am retiring into the Philippines this year and I would like to build a house cob style and I was hoping for some advice. Regards
chunky - 22-Jan-17 @ 3:52 PM
baby - Your Question:
I am from india(tropical place). you have not mentioned anything about pest control(termites) and maintainance.will cob houses withstand 4 months of lashing monsoons?thank you.

Our Response:
This site is created here in the UK and is based on UK climate etc, so we cannot really advise you on this.
SustainableBuild - 4-Mar-16 @ 2:29 PM
i am from india(tropicalplace). you have not mentioned anything about pest control(termites) and maintainance.will cob houses withstand 4 months of lashing monsoons?thank you.
baby - 3-Mar-16 @ 5:43 AM
In para 3 you say "Solid wall structures such as stone, cob and adobe cannot be insulated".This startling news is likely to have a profound effect on the thousands of retro fit schemes that have done precisely this.I will also rush home and rip out all of the internal solid wall insulation I have installed in my house... ...or put another way, please be careful that when you publish something...you get it right! masonry, stone and cob walls CAN be insulated, very effectively.
Dekay - 21-May-15 @ 4:15 PM
How geopolymer concrete works in ecofriendly building? Could you explain geopolymer concrete usage in green buildings?
Vdss - 4-Jan-15 @ 7:34 AM
@Karendeburca. We're conjuring up lovely pictures of a ragstone cottage with oak windows and porches here! Is that what your property is like. First of all is the wall visible between the porch or is it a solid oak panel? Not really clear from your question sorry.
SustainableBuild - 9-Jul-14 @ 11:07 AM
Is there a way of insulating between ragstone and oak? We have an oak porch which is attached to a ragstone wall, however, there are small gaps between the ragstone and the porch which make the porch chilly in winter.
karendeburca - 8-Jul-14 @ 10:42 PM
@Mack. Yes they do. Rice hulls have been used in several green build projects over in the states. They have the advantage of being lightweight, good for transportation and once packed into bags, hold their shape & have quite good load bearing properties.
SustainableBuild - 11-Jun-14 @ 12:30 PM
i would like to know if rice hulls have insulating properties ?
mack - 11-Jun-14 @ 11:39 AM
Earthing material manufacturer plays a crucial role in installation and distribution of High Tension and Low tension power supply. Our quality earthing material includes Crimping Legs and sockets, Hot dip Galvanizing Cross arms, Earthing Pipes, Earthing Strips, Pipe Electrodes, Earthing Plates, Earthing Wire etc.
gmel - 1-Aug-13 @ 7:48 AM
What about recycled plastic insulation like non-itch and green loft ?
lol - 24-Aug-11 @ 9:35 AM
Share Your Story, Join the Discussion or Seek Advice...
(never shown)
(never shown)
(never shown)
(never shown)
Enter word:
Latest Comments
  • SustainableBuild
    Re: Brownfield Sites
    Swedish Fish - Your Question:We own land which was a former manmade millpond and water management system including stone sluices, stone culverts…
    21 November 2017
  • Swedish Fish
    Re: Brownfield Sites
    We own land which was a former manmade millpond and water management system including stone sluices, stone culverts and man made mill bypass…
    20 November 2017
  • Badgerboy
    Re: Environmentally Friendly, Non Toxic Paint
    Turpentine is toxic Resins derived from natural oils such as Linseed oil can give off V.O.C.s These can cause…
    15 November 2017
  • Martin
    Re: Stone Construction
    Hello. I'm a stone builder from Argentina. I built two houses on my own using limestones, or granite limestones. I'm not good at classifying…
    11 November 2017
  • Rachel
    Re: Straw Bale Construction
    Hello, I'm looking for suppliers of good quality straw bales in Pembrokeshire, does anyone have any tips?. We're near Lanycefn and need…
    6 November 2017
  • SustainableBuild
    Re: Brownfield Sites
    don - Your Question:I own a small site (6 houses possibly) that was a resevoir with pumphouse, the pumphouse was demolished due to vandalism so…
    3 November 2017
  • don
    Re: Brownfield Sites
    I own a small site (6 houses possibly) that was a resevoir with pumphouse, the pumphouse was demolished due to vandalism so was not considerd…
    3 November 2017
  • Prathibha
    Re: Greenfield Sites
    I want to know about the techniques used to survey a large greenfield site
    1 November 2017
  • Linda
    Re: Grants and Loans for Green Development
    Hello my name is Linda Roberts and I am enquiring how I apply for support. I am trying to purchase and restore a…
    22 October 2017
  • AMLH
    Re: Underground Construction
    Hi, We have some land which we want to put underground rooms in, for holiday lets. Can anyone please tell us, where I can buy prefab…
    14 October 2017
Further Reading...
Our Most Popular...
Add to my Yahoo!
Add to Google
Stumble this
Add to Twitter
Add To Facebook
RSS feed
You should seek independent professional advice before acting upon any information on the SustainableBuild website. Please read our Disclaimer.