Most homes will already have some loft insulation. The Energy Saving Trust currently recommended a minimum depth of 270mm or 10½" of mineral wool or equivalent. Depending on the type of insulation you choose, the actual depth can vary because some materials are better than others. The main types include:
| type | brands |
| Solid foil backed foam board | Celotex PIR sheet |
| Foil backed closed cell rolls | Airtec |
| Sheepswool batts |
Thermafleece |
| Mineral and glass fibre rolls and batts | many brands |
| Hemp fibre | Isonat |
| Recycled cotton batts |
Innotherm |
| Loosefill cellulose (recycled paper) | Warmcell |
The type of insulation you choose will depend on your budget and the space available in the loft. Some materials have environmental advantages; by recycling materials less energy is used in manufacture. You may need to create a raised platform if you wish to use your loft as a useful storage space as squashing the insulation material will reduce its insulating properties.
The investment can soon pay for itself. Typical figures:
Insulation type: Mineral and glass fibre loft insulation
Annual saving: As much as £220 per year
Cost: From around £385 (installed) Payback: Around 2 years
Note that loft spaces require minimum
ventilation to avoid
condensation
buildup and particular care if your boiler is in the loft.
Insulation should not be laid over electrical cables as they could overheat and catch fire. New electrical safety law now means that domestic electrical wiring needs to be installed by or certified by an NICEIC approved electrician. You can do the work DIY, but it must be certified afterwards. Check by phoning 0870 013 0381 or see www.niceic.org.uk.