Often made from recycled newspapers, cellulose fibre is a loose fill insulation.

Description
As a loose fill insulation it does not come in blankets, sheets or boards, rather as a loose fibres that are blown or laid into place and must be protected from drafts or breezes. Additionally, to maintain optimal performance it must be kept dry. It is treated with boron salts to provide insect protection and fire resistance. It can absorb and release moisture without significant impact on its insulating characteristics.

• Non-toxic & non-irritating.
• Biodegradable.
• Renewable.
• Locks in carbon.
• Low embodied energy. As little energy is consumed in its production, Cellulose Fibre has one of the lowest embodied energy ratings of all types of insulation.
• Loose Fill. Easy to install - no tools required. Protection from the wind and rain is necessary. Can be applied by sprayer. Can be used to fill irregular shapes that may otherwise be awkward to insulate in and around.

Note: Compression of the fibre must be avoided - without sufficient trapped air insulating effectiveness will be compromised.

Performance
Cellulose Fibre has a thermal conductivity or K value of 0.035 W/m.K.
(Watts per meter Kelvin ~ a lower value is a better result)

Cost
Made on a relatively large scale from recycled materials, costs are reasonable.

Representative cost:
Usually for sale in bags.
Approximate cost per square metre at 100mm depth is around £4.

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I promised I’d post a picture of the view from the gable end bedroom so here it is.

the view across the valley

I’m pleased with the window and the view and light that it provides - the thick wall and small window provide a narrow glimpse of the outside. A slight shame in that a wider window could have really opened up the far-reaching view, but as this window was a late amendment to the plans I’m just glad it’s there.

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Perhaps one of the most talked about and attractive recent innovations, sheep’s wool insulation is of particular attraction to those of us who to the woolly West or North of the UK. But does it live up to the hype?

the donor!

Description
Sheeps wool is a renewable by-product of the farming industry. It has extremely low embodied energy is in plentiful supply and can act as a humidity regulator as it can absorb up to 40% of its own weight in water, the water being released when conditions change. It is a natural non-toxic, non-irritating material.

Features

• Non-toxic & non-irritating.
• Biodegradable*.
• Renewable.
• Low embodied energy.
• Adapts and fits well. Suitable for use in walls, floors and roofs.
• Fire resistant. Wool melts and extinguishes itself in contact with flame.

* Note: Some products contain polyester as a ‘lofting’ agent (an additive to ensure that the material maintains its structure and air trapping ability over its lifetime). This is usually a blend of recycled and ‘virgin’ polyester. The polyester is at a low enough concentration in the final product to not effect biodegradability.

Note: Early products were somewhat stigmatised due to the reputed use of chemicals in the production process and to improve structure, durability, moisture & insect protection as well as concerns over chemical residues left by sheep dipping. Rubber or polyester and borax (a compound of boron which is a mineral salt of boric acid) tend to be used for these purposes now, thus mostly doing away with such concerns. Testing has concluded that the risk from sheep dipping is negligible.

Performance
At a density of 25kg/m3 sheeps wool has a thermal conductivity or K value of 0.039 W/m.K.
(Watts per meter Kelvin ~ a lower value is a better result)

Cost
As production is still relatively small scale, cost is high relative to other materials.

Representative cost:
A 75mm x 400mm x 1200mm roll of batts costs approximately £90 (rounded) including VAT and covers 12.96 m2 therefore approximate cost per square metre at 75mm depth is £7.

Other Information
It’s has even made it into the Independant Newspapers Top 50 Great Ideas for the 21st Century …

References:
http://www.sheepwoolinsulation.ie
http://www.secondnatureuk.com
http://www.blackmountaininsulation.com

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We have windows and a couple of doors, both big and small and all of them white. They’re not all in yet, but we’re getting there.

a new white window…

The windows are hardwood and were hand-made relatively locally from (sustainable we are told) African hardwood.
I never intended to go for hardwood windows - softwood seemed [...]

From a full Passivhaus design to a simple loft conversion the effective use of insulation has never been more high profile. One of the key features of current renovation and new building design is the effective utilisation of insulation to minimise heating requirements. Whilst in the UK we historically tended to think of insulation in [...]