Insulation Type
Cavity Wall Insulation
Stop up to 35% of heat escaping through your walls with cavity wall insulation — fully funded through government grant schemes.
What Is Cavity Wall Insulation?
Most homes built after the 1920s have cavity walls — two layers of brick or block with a gap (cavity) between them. Without insulation, this gap allows heat to escape, making your home harder and more expensive to keep warm.
Cavity wall insulation fills this gap with an insulating material, typically injected through small holes drilled in the outer wall. It is a quick, minimally disruptive process that can dramatically reduce heat loss and lower your energy bills.
Up to 35%
Heat Loss Prevented
£150–£330
Annual Savings
1–2 hours
Install Time
£0
Cost to You
Check If You Qualify for Free Cavity Wall Insulation
Enter your postcode to start your free eligibility check.
Benefits of Cavity Wall Insulation
Here's what you can expect when cavity wall insulation is installed in your home through a government grant scheme.
How It Works
Check eligibility
Enter your postcode to see if you qualify for free cavity wall insulation through ECO4 or GBIS.
Home survey
A surveyor inspects your walls using a borescope to confirm they are cavity walls and checks for suitability.
Installation
Small holes are drilled in the outer wall and insulation is injected into the cavity. The holes are then sealed and made good.
Start saving
Your walls immediately retain more heat, reducing energy consumption and making your home noticeably warmer.
Register Your Interest
Leave your details and we'll contact you about free cavity wall insulation.
Frequently Asked Questions
Other Insulation Types
Loft Insulation
Reduce heat loss through your roof by up to 25% — one of the simplest and most cost-effective energy efficiency measures.
External Wall Insulation
Wrap your home in a thermal layer to cut heat loss by up to 45% — ideal for solid-wall properties.
Internal Wall Insulation
Insulate solid walls from the inside to reduce heat loss by up to 40% without changing the exterior of your home.
Check Your Cavity Wall Insulation Eligibility
Enter your postcode to find out if you qualify for free insulation through government grants.