How much can you save with cavity wall insulation?
Cavity wall insulation can save you money on your fuel bills and help the environment as well as keeping your home warm and cosy – find out how much you could save here.
“We use more energy to heat our homes than they do in Scandinavia where it’s twice as cold,” says architectural designer and TV presenter Charlie Luxton. “This is because we have such old, poorly insulated housing stock.” Insulating houses is one the governments key strategies to reduce household carbon emissions by 90% by 2020. Along with loft insulation and installing an energy efficient boiler, cavity wall insulation is one of the best ways to lower your household carbon emissions, stay warm and save money.
The benefits of installing cavity wall insulation
Installing cavity wall insulation can:
- Save you money
- Help the environment
- Keep your home warm
- Reduce household condensation
- Increase your home’s value and saleability
- Require no maintenance and last the lifetimeof the building
What is cavity wall insulation?
”The key thing with any eco-home improvements is to start with the insulation and walls are a massive problem,” explains Charlie. According to the Energy Saving Trust (EST), most homes built around or after 1920 have cavity walls. This means that there are two external walls separated by an air filled gap, which was originally designed to prevent damp. If this cavity is filled with insulation, it can reduce the amount of heat lost through your walls. One third of your home’s heat is lost through the walls but cavity wall insulation can significantly reduce this, lowering the U-Value of your walls (the U-Value measures the rate at which heat is lost through your walls). Homes built within the last ten years will normally already have cavity wall insulation, if you’re unsure whether your home has solid or cavity walls, ask an insulation professional.
The materials normally used for cavity wall insulation are:
- Polystyrene beads
- Urea Formaldehyde foam
- Glass or rock wool
How much can cavity wall insulation save you?
According to the EST, installing cavity wall insulation can save you up to £110 off of your fuel bills and 560kg of CO2 per year based on a three-bed, gas heated semi-detached home. The Cavity Insulation Guarantee Agency (CIGA) say that every square meter of cavity wall insulation will save more than a tonne of CO2 over the lifetime of the building.
Installing cavity wall insulation
Property expert Michael Holmes advises: “When you are planning a project always see whether you can improve or repair the structure first before you consider any cosmetics, make sure it’s warm, dry, insulated and structurally sound.” So when planning to insulate your home, you first need to make sure that it’s suitable for cavity wall insulation, which it will be if:
- The external walls have an unfilled cavity of at least 50mm wide
- The brickwork of your exterior walls is in good condition
It is essential that you hire a qualified insulation company to install cavity wall insulation; they will carry out a pre-assessment first to double check that your home is suitable. The EST recommends hiring someone registered with one of the following organisations:
- The Cavity Insulation Guarantee Agency (CIGA)
- The British Board of Agrement (BBA)
- The National Insulation Association (NIA)
To install the insulation the contractor will normally drill a series of holes of approximately 25mm in diameter into the exterior walls of your home and then inject insulation into the cavity, taking care not to block any ventilation. According to the CIGA it can take around two hours to install cavity wall insulation depending on the size of the house and ease of access to the walls.
Always get at least three quotes for cavity wall insulation and check references, qualifications and insurance credentials. A credible cavity wall insulation installerwill use materials which meet British Standards and should last the lifetime of a house. They should also provide you with a certificate to prove the work has been carried out, for instance the CIGA will provide a 25 year guarantee.
How much does cavity wall insulation cost?
Prices for cavity wall insulation may vary depending on the size of the property but the EST suggests that it could cost around £250.
Grants for installing cavity wall insulation
As well as introducing the new Green Deal, which offers homeowners loans to install household insulation, there are some grants available to help vulnerable households install insulation. The Carbon Emissions Reduction Target (CERT) also requires energy companies to provide efficiency measures such as installing cavity wall insulation to customers – your don’t even have to get one from your current energy supplier. To find out if you’re eligible for a grant, contact your local council.