better generation

Insulating your loft is as easy as it gets in order to saving money and reducing your climate change impacts. Around 25% of heat in an un-insulated house is lost through the roof, and you can save as much as 20% of your energy bill by installing good thermal insulation. As recently as 2008, the government and energy companies made £910 million in the form of insulation grants available to homeowners and tenants towards the cost of insulating their home, which should help to reduce energy bills.

Loft insulation is effective for at least 40 years and pretty much pays for itself during that time through money saved on your heating bills. Furthermore, almost everyone is entitled to a grant from the government that covers 40-70% of the cost. If you already have loft insulation but it is less than 270 mm then you could still get a top up.

How does it work?

Loft insulation works by stopping the upwards movement of heated air, reducing the loss of heat from the rooms below, which of course will then require less heating. Material is normally installed between the wooden joists in the floor of the loft. If your loft space is converted into an attic that you use, you should insulate the sloping sides of the roof structure itself.  A guide on DIY loft insulation is available here.

If your house has an accessible loft with no damp or condensation problems, then it should be suitable for insulation. However, if your loft is difficult to access then it may be possible to still insulate through blow insulation but this must be done by a professional installer. A flat roof can be insulated from the inside and the outside. The best time to insulate externally is when you are decorating or renewing the waterproof covering, which is normally when it is about 15 to 20 years old. It would involve laying boarding backed with insulation material either on top or under the waterproof covering. Internal roof insulation is done also through insulation backed boards. However, it would be best to get professional installers to do this.

What types are available?

• Rolled or blanket insulation is usually made from mineral wool or fibreglass. In the UK a thickness of at least 270mm (8in) of rolled insulation is recommended. These types are fairly straightforward to self-install, but irritate the skin so make sure you wear proper protection from the fibres. Alternatively you could use blanket insulation made from the blended wool of british hill sheep. It has the benefit of being totally natural, non-irritant, non toxic and fully complies with british standards (but it will cost you more).
• Loose fill or granular insulation, available as bags of loose-fill, granular insulation material which is fairly straightforward to self install. There are also loose-fibre types which are designed to be blown into place by a machine - this is a job for a professional. A green alternative is loose insulation made from recycled newspaper.

How much does it cost?

Depending on size and amount required, it should cost around £250, with subsidies, to install the insulation yourself. An installer might charge a little more, however, the job should take around 2 hours to complete for an average-sized loft. The cheapest type of insulation is fibreglass or mineral rolled blanket insulation.  If your budget stretches to it, we recommend considering one of the green alternatives – high performing equivalent products made from recycled newspaper, or processed sheep’s wool. See below.

Where can I buy it?

For fibreglass or mineral rolled blanket insulation, check out your local DIY store. Sheep's wool insulation can be bought from your local distributor of Thermafleece - see www.secondnatureuk.com.  Loose-fill loft insulation made from recycled newspaper such as Warmcel 100 can be bought via the distributors listed here.

Grants