Carbon Saved by Insulating Your Home
By far the greatest cause of heat loss in the home, up to 67%, is due to inadequate insulation. Of this, as much as 33% is lost through cavity walls, 26% through the loft and 8% through the floor.
Poor insulation wastes over £1.4 billion a year in heating costs, and 15 million tonnes of CO2.
Amount of CO2 saved annually by adding insulation:
Cavity wall insulation = 750 kg
Solid wall insulation = 2,500 kg
Loft insulation:
adding 270 mm insulation where none exists = 1,000 kg
topping up existing insulation to 270mm = 250 kg
Floor insulation = 470 kg
For walls, we have assumed a cavity wall insulation figure of 750 kg as most houses built after the 1920s/30s have cavity rather than solid walls.
For lofts we have assumed that most houses without adequate insulation will already have some that only requires topping up.
Average carbon saving from insulating walls, lofts and floors:
(750 + 250 + 470) /3 = 490 kg CO2 annually.
Installing Insulation In Your Home
Cavity Wall Insulation
Most homes built after the 1920s/30s have cavity walls. Having these filled will keep the heat in during the winter, the heat out during the summer, and could save 750 kg CO2 per year. Also, as well as lower heating bills, your boiler may last longer too as it does not have to work so hard.
You can tell if you have cavity walls by the pattern of the brickwork; generally bricks in cavity walls are laid lengthwise and look to be the same length.
Installing the insulation is a professional job, and involves injecting insulating material into the cavity by drilling small holes in the external walls. There are three types of material commonly used: mineral wool, UF Foam (Urea Formaldehyde foam) or expanded polystyrene beads, and all are treated to be fire and rot resistant, and repel water. Mineral wool is spun from rock or glass and blown into the wall; UF foam is formulated on site and injected as a wet foam which expands to fill the cavity, setting immediately. The third type, expanded polystyrene beads, are injected together with a binder or adhesive. The holes are re-filled afterwards, and the whole process takes around 2 to 3 hours.
The Cavity Insulation Guarantee Agency (CIGA) provides a 25 year guarantee covering installations carried out by registered CIGA installers.
Of the 25 million households in the UK,
6 million homes have already had installations, but there are still 10 million un-insulated homes. If every home was insulated it would save 7.5 billion tons of CO2 a year.
Solid Wall Insulation
It is possible to insulate solid walls, by either applying a decorative insulating material to the outside walls, or fitting insulating boards to the internal surface. Although the process tends to be more expensive than cavity wall insulation, you may be able to almost cut your heating bill by half,
and save over 2 tonnes of CO2 per year.
It is recommended that the materials used are approved and covered by British Board of Agrément certificates.
Loft Insulation
Loft insulation should ideally be topped up or installed to a depth of 270mm. The materials used may be either mineral wool quilt, blown mineral wool or blown cellulose fibre,
and installing adequate insulation can save up to 15% of your heating costs.
Floor Insulation
As with loft insulation, rolls of mineral wool can be laid beneath floorboards between the joists, saving 350 kg of CO2 per year. Using silicone sealant to fill in gaps between the skirting boards and floorboards will save a further 120 kg of CO2 per year, and it may be possible to do this yourself.
Where to find installers:
Insulation Installers Directory (UK)
http://www.insulation-installers.co.uk
Cavity Insulation Guarantee Agency (CIGA)
http://www.ciga.co.uk/installers.html
National Insulation Association (NIA)
http://www.nationalinsulationassociation.org.uk/housholder/householder-nia.html
Further Resources and Information
National Insulation Association (NIA) (covers all insulation and draught-proofing)
http://www.nationalinsulationassociation.org.uk
Cavity Insulation Guarantee Agency (CIGA)
http://www.ciga.co.uk
Energy Saving Trust
http://www.energysavingtrust.org.uk/home_improvements/home_insulation_glazing
Insulation products: http://www.energysavingtrust.org.uk/compare_and_buy_products/insulation
British Board of Agrément (certification for solid-wall materials)
http://www.bbacerts.co.uk
