Cavity Wall Insulation

Fast facts

  • Free Cavity Wall Insulation available for everyone with a suitable home
  • Keep your home warm in winter
    and cool in the summer
  • Savings of more than £250 per year off your energy bills


“Mark Group were very professional when fitting the cavity wall insulation and the house was left very tidy. We have noticed an improvement in the property and even through the cost of gas has risen, our bills are now less.”

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Up to 35% of all heat loss in your home is lost through the walls. Most modern homes are built by constructing masonry walls with an air-gap, or “cavity”, of at least 50mm in between. Insulating this cavity is one of the best ways to reduce the amount of energy you need to heat your home.

How does Cavity Wall Insulation work?

Most modern homes are constructed with an ‘air-gap’ or cavity walls, and filling this with insulating material can significantly reduce heat loss. However, not all homes are constructed in this way, and as such, your home will need to be surveyed to make sure it is suitable first.

Once this has been confirmed, our insulation team will drill a series of small holes into the outside wall of your property. Then, they will insert insulating material into the cavity using specialist equipment.

The insulating material can be made from a variety of different materials, but is usually made from recycled granulated mineral wool fibre or polystyrene beads. In effect, this creates a blanket effect that will prevent heat escaping.

This means that you use less energy to keep your home warm, helping you save money on your bills.

Guide to Cavity Wall Insulation

Check out our brand new guide to installing Cavity Wall Insulation in your home.

Cavity Wall Insulation is one of the quickest and simplest ways of reducing your monthly bills and our handy video explains how it works and what it can do for the energy efficiency of your home.

Not sure if you have cavity or solid walls? We've even included a great little hint to help you figure it out yourself!

Why choose Mark Group?

Mark Group is an expert in insulation and energy efficiency when it comes to your home. We help over 7,000 homes, schools and businesses every week. We pride ourselves on offering excellent service, peace of mind and value for money.

Once you have had your cavity wall insulation fully installed, we will obtain a 25 year guarantee for you, so you know that you’ll have a cosy home for years to come.