The Energy Saving Trust reckons cavity insulation typically costs up to £725 to install (including building work), and can save between £70 and £255 per year on your energy bills, depending on your home. Loft insulation costs up to £395 and can save between £120 and £225 a year.
Government Grants – £5000 Voucher
The Government has announced that up to £5,000 in vouchers will be issued to homeowners in England for energy efficiency improvements, such as installing loft, floor and wall insulation, or double-glazing.
Under the new Green Homes Grant scheme, which launches in September, for most homeowners the vouchers will be worth about two-thirds of the cost of the energy efficient improvements they’re making, up to a maximum of £5,000 per household.
You can apply for the vouchers online here.
Cavity wall and loft insulation is worth up to £1,100 and can slice up to £480/year off energy bills. Energy firms are offering it for free, as long as you own your home and meet their eligibility criteria – but make sure it’s right for your home first.
- Cavity wall insulation. Most homes built between 1920 and 1990 have a gap between internal and external walls. Filling the cavity with insulating material means cold air’s kept out, and warm air stays in – but it’s not suitable for all.
- Loft insulation. Up to a quarter of your home’s heat escapes through the roof, but you can limit this by laying mineral wool under the rafters.
Cavity wall insulation ISN’T right for everyone
Installed properly and in appropriate properties, cavity wall insulation can improve energy efficiency and cut home heating bills. Yet there has been a catalogue of horror stories of major damp and mould problems emerging after installation – with claims it’s cost some £1,000s to fix, and even impacted their health.
If you’re considering cavity wall insulation, it’s vital to first check that it’s suitable for your home.
- What’s the problem? A 2016 report by the Building Research Establishment looking at cavity wall insulation in Wales – where many problems have been reported – concluded there is evidence it’s been poorly installed, or installed in unsuitable properties in some cases. Problems seem to be concentrated on the west side of the country, including in south-west England, west Wales, north-west England and north-west Scotland. These areas are known to be particularly unsuitable for cavity wall insulation because of severe exposure to ‘wind-driven rain’.
- How can I check if cavity wall insulation is right for my home? First check whether the area you’re in is deemed high risk. The map below from the Building Research Establishment shows the areas that are most at risk of ‘wind-driven rain’ in blue and dark blue. According to the Energy Saving Trust, if you’re in one of these problem areas, it’s likely your home isn’t suitable for cavity wall insulation. It’s not just about location though – you should also check that your property itself is suitable. The Energy Saving Trust says it’ll usually be suitable for cavity wall insulation if:
- Its external walls are unfilled cavity walls.
- The cavity is at least 50mm wide.
- The masonry or brickwork of your property is in good condition.
- It was built before 1990 (most newer houses will have insulation already).If you do want to get ahead with cavity wall insulation, make sure your installer is registered with the Cavity Insulation Guarantee Agency (CIGA). Finally, if you’re still unsure, get a second opinion from another installer. Don’t proceed unless you’re sure it’s right for your home.
- What can I do if I have problems with my insulation? If you do experience problems with your home after cavity wall insulation is installed, you should first complain to the company that originally carried out the installation. However, if it was a while ago you may find it no longer exists. If that’s the case – or if it does exist but isn’t able to give you a satisfactory resolution within 41 working days – you can contact the Cavity Insulation Guarantee Agency (CIGA). It will investigate your complaint free of charge – all cavity wall insulation fitted by registered installers is covered by a 25-year guarantee overseen by CIGA, so if it finds in your favour it can help cover the cost of any repairs or any other needed work up to a value of £20,000. If CIGA fails to help, or you disagree with its decision (and some have reported problems), you can escalate your case to an independent arbitrator run by the Centre for Effective Dispute Resolution. You’ve 12 months from the date CIGA issues its final decision to take it to the independent arbitrator. However, you’ll need to pay £25 plus VAT to refer your case, and all decisions are final and legally binding. The Cavity Insulation Victims’ Alliance (CIVALLI), a volunteer-led organisation set up by people who have had major problems with cavity wall insulation, may also be able to help. It provides plenty of information and guidance on what to do if you have had issues, and can help people fight their case.
- Why has cavity wall insulation been installed inappropriately? Though there’s been no official verdict on how and why some cavity wall insulation has been installed inappropriately, some have blamed Government energy efficiency targets and the money made available to installers by energy companies – who could be fined if they fail to meet those targets. This may have led some installers to push insulation where it may not have been suitable.