The Energy Saving Team

Insulating your cavity wall is a very effective way to reduce your heating bills immediately & make your home much warmer.

If your home was built from 1920 onwards, the chances are that its external walls are made of two layers with a small gap or 'cavity' between them, a bit like double-glazing. This cavity may be suitable for insulation.

*based on 3 bed gas heated semi-detached

Why insulate your cavity walls?

You lose the greatest amount of heat through your walls - up to 35%

This is because the walls have the biggest area exposed to the outside compared to your loft or even windows & doors.

Cavity wall insulation can also help reduce condensation & mould inside the house, especially around windows.

How much does it cost ?

Most of the cost for insulation is paid for using the government grant - you typically contribute just £149*. If you are over the age of 70 or on qualifying benefits, it may be Free.

With estimated annual savings on your heating bill of up to £115- your pay back can be just over a year.

As you have already paid for the grant, you can get the walls insulated professionally . All the work is guaranteed for 25 year s by an independent government backed agency known as CIGA (Cavity Wall Insulation Guarantee Agency, who provide you with a valid Certificate of Insulation

*based on 3 bed house & subject to survey. Larger properties typically cost £179 using the grant.

Common Questions & Answers

• Do I Qualify?
  If the cavity is suitable for filling then you would qualify as long as 75% of the house can be insulated. The Surveyor will use a special camera called a boroscope to look inside the cavity to determine if the cavity is suitable for insulation.
• I have solid walls?
  Unfortunately, there are no grants to assist however your loft may still qualify for insulation. We can recommend external render insulation which will preserve the building, provide sound proofing & insulation at the same time.
• I live in a flat?
  Ideally it is best to get the whole block insulated, however we can do just a column of flats directly above one another up to 3 stories high.
• How much will it cost for a larger house?
  For detached properties with 4 or more bedrooms, the costs is generally £179.
• Are there any additional costs?
  Generally, no - however there may there may be an additional charge of up to £50 should a safety vent be required , which allows adequate ventilation in a room if you have a large gas fire (over 7KW) or an open fireplace (if it can be used)our type of property. There may there may be an additional charge of £4 per m2 should insulation be required if it is above the government maximum allowed area for your type of property. Some properties may require scaffolding to allow access to certain walls.
• I have an extension?
  There may be an additional charge of up to £4 per m2 should insulation be required if it is above the government maximum allowed area for your type of property
• What material is used?
  Knauf Supafil Cavity Wall Insulation is a glass mineral wool which is injected in a loose form, looks a bit like cotton wool providing excellent insulation. It 's fire proof & provides resistance to weather and ground moisture as it does not absorb water by capillary action.
• Can it cause Damp?
  No -the underlying cause of any damp must be first treated before the cavity wall is insulated. The insulation material used provides resistance to weather and ground moisture, as it does not absorb water by capillary action.
• I have a conservatory?
  It may be possible to use a specialist conservatory ladder to insulate the bedroom wall above . The original outside wall would also need to be insulated inside the conservatory.