What is Cavity Wall Insulation?

Understanding Cavity Wall Insulation: A Key to Energy Efficiency

Cavity wall insulation is a critical technique in enhancing the energy efficiency of a property. The process involves filling the space or ‘cavity’ between the inner and outer layers of a building’s walls. This type of insulation is crucial in preventing heat loss through walls, thereby playing a significant role in enhancing a property’s overall energy efficiency. This can lead to not only lower energy costs but also contributes to a more comfortable living environment.

Diverse Materials for Insulation in UK Homes

Mineral Wool

One of the most common materials, mineral wool, is environmentally friendly as it is made from recycled glass. Its fibrous structure makes it effective for trapping air, thus providing excellent insulation.

Expanded Polystyrene Beads

Another popular choice, these beads are lightweight and made from recycled plastics. They are particularly effective in filling irregular spaces and providing uniform insulation.

Foam Insulation

Foam insulation offers a higher level of thermal resistance and is ideal for properties requiring maximum insulation.

Cellulose Insulation

Made from recycled paper, cellulose insulation is both eco-friendly and effective, especially in reducing air infiltration.

Benefits of Cavity Wall Insulation

The advantages of cavity wall insulation extend beyond just energy efficiency:

  • Increased Energy Efficiency: This is the primary benefit, as insulation reduces the amount of heat lost through walls, thus requiring less energy to maintain a comfortable indoor temperature.
  • Lower Energy Bills: With improved insulation, homeowners can enjoy significant reductions in their energy bills, often seeing a noticeable difference.
  • Enhanced Comfort: Insulation helps maintain a consistent indoor temperature, contributing to a more comfortable living space.
  • Environmental Impact: By reducing the need for energy consumption, cavity wall insulation plays a vital role in lowering the carbon footprint of a property.

Potential Energy Savings

The energy savings from cavity wall insulation can be substantial, depending on various factors such as the property’s age, construction, the type of insulation used, and existing insulation levels. Estimates suggest that proper cavity wall insulation can save up to 25% on energy bills, which can amount to a considerable financial saving annually. 

Typical installation costEnergy bill savings
Detached house£1,800£475/year
Semi detached house£1,000£361/year
Mid-terrace house£580£203/year
Detached bungalow£800£337/year
Purpose built flat£395£234/year


These estimated figures were provided by the Energy Saving Trust and the National Housing Model, based on a gas-heated household. The average cost of installation presented here is without subsidies. These numbers are calculated using fuel prices from October 2022.

JNR Projects: Your Trusted Partner in Cavity Wall Insulation

At JNR Projects, our expertise in cavity wall insulation positions us as your ideal partner in enhancing your property’s energy efficiency. We offer a diverse range of insulation solutions tailored to meet the specific needs of your property. Whether it’s mineral wool, polystyrene beads, or foam insulation, we can guide you in selecting the most suitable option. Our team’s extensive knowledge and experience ensure that your property is in capable hands.

Take the Next Step

To learn more about how cavity wall insulation can benefit your property, or to schedule a free consultation, please contact us. Our team is ready to assist you in taking a significant step towards energy efficiency and environmental responsibility.