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Cavity Wall Insulation

Cavity wall insulation is a system whereby insulating material is injected into the gap (or cavity) between a property’s inner and outer walls. It reduces the amount of heat escaping from your home into the outside world and keeps the warmth inside your home making you warm and cosy when you need to be.

It also works in reverse keeping you cooler in the summer months.

Domestic and General installed cavity wall insulation in over 15,000 homes last year, which means our installation teams are installing insulation in around 40 homes per day around the country. 

Homes with cavity wall insulation save, according to The Energy Saving Trust, around £110 per year on their heating bill and prevent around 560kg of CO2 being emitted into the atmosphere.

Furthermore, grants are offered by the Government and energy companies to make cavity wall insulation more affordable. In some cases, you may even be entitled to insulate your home for free.

Features and Benefits

Cavity wall insulation provides a good return on a relatively small investment.

Installed from around £99 for the average three-bed semi detached property, you can expect savings of £110 per year, according to the Energy Savings Trust, on your heating bill meaning it can pay for itself in in the first full year after installation. Furthermore, everyone is entitled to some level of non-repayable grant funding towards the cost of cavity wall insulation making it even more cost effective. Some people even qualify for free


  • Provides a high level of thermal efficiency – warm in winter; cool in summer
  • Reduces energy consumption and therefore heating bills
  • Less demand on boilers
  • Reduces condensation and black mould growth
  • No maintenance required
  • No disruption to inside your home
  • Quick installation times – around two hours for a three-bed semi detached house

 Key features

  • All Systems are BBA (British Board of Agrément) approved
  • A variety of insulation systems available

One of our surveyors will be able to explain the various benefits of each type of insulation to you whilst visiting your property.

  • Thermabead 06/4300
  • Thermabead Carbonsaver 06/4300
  • Thermabead Diamond 06/4300
  • Polypearl & Polypearl Plus 96/3228
  • Yellow Wool 88/1976
  • White Wool 89/2294
  • Rockwool 95/3149
  • UF Foam BS5617/5618
  • Walltherm 96/3274
  • Cosytherm White Wool 01/3798

The Product

Domestic and General are fully accredited to install a wide range of cavity wall insulation systems meaning we are able to specify the system best suited to your property and your budget.

The Process

  • One of our friendly surveyors visits your property to advise you on the cavity wall insulation system that will best suit your property.
  • Our surveyor will advise you of the cost for installing cavity wall insulation and any non-repayable grant that you may be entitled to.
  • We arrange a convenient time for one of our installation crews to come and carry out the work.
  • All loose items around the property are removed and temporarily stored away from the wall surface. Existing pipes, services, balanced flues and airgrades are checked to determine functionality. If required, any plant growth is either restrained or cut back to clear the working area.
  • Installation of the insulation commences once site is prepared and safe. Each elevation of the property has small holes drilled out in compliance with the BBA specification so that insulation can be blown through the outer wall into the cavity.
  • Once all walls have been treated, the holes are filled and the site is cleaned and previously removed items are replaced.
  • Final inspection of site is completed with you before the job is signed off. You enjoy reduced heating bills in a warm and cosy environment

What else can I do to insulate my home?

Deciding to insulate your cavity walls is a great first step to achieving better energy efficiency for your home and the associated reductions in your heating bills. However, to really capitalise on reductions in heating bills through energy efficiency, you should also consider insulating your loft space too