GB Insulation Scheme FAQs

Cavity wall insulation fills the empty gap between your home’s inner and outer walls with a specialist insulating material such as mineral wool or polystyrene beads. It prevents heat from escaping through the walls, keeping your home warmer in winter and cooler in summer.

We only use polystyrene beads; it is a far better insulating material than mineral wool.

or call us on 0800 8 10 10 60 or 07960 799681 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Homes built between the 1920s and 1990s often have a “cavity” between two layers of brick.

By injecting insulation into that space, we create a thermal barrier that traps warmth in the house and reduces draughts — helping your heating system work far more efficiently.

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

There are 2 routes to qualifying for a grant.

The “Low-income” Group and The General Group.

The General Group qualification for a grant.

1. Your Council Tax Banding must be an A, B, C or D in England (or in Wales, it must A, B, C, D or E). You can find your Council Tax Banding on Gov.Uk, and
2. Your EPC (Energy Performance Certificate) rating must a D, E, F or G. You can find your EPC on the EPC Register. 

If you can answer Yes to both of the statements above, you qualify for a grant. Don’t worry if your home does not have an EPC, we will produce one.

The “Low Income” Group qualification for a grant.

The personal qualification criteria for the “low income” group is benefit-based.

Here is the list of Qualifying Benefits.

• Pension Credit 
• Income-Based Job Seekers’ Allowance
• Universal Credit – No income threshold
• Income-Related Employment and Support Allowance
• Tax Credits (including Working and Child Tax Credits) – No income threshold
• Income Support 
• Housing Benefit – NEW
• Child Benefit/Family Allowance. Income Thresholds apply – see table below

Do I qualify for a Grant if I get the Child Benefit?

Yes, you would qualify for a grant if you claim Child Benefit and have an annual income no greater than the appropriate threshold.

The threshold varies between single people and couples, and depends on the number of children you have. See the table below. So, 2 adults with 2 children would have an income threshold of £32,300 (before deductions)

Number of children	1	2	3	4
1 adult household	£19,900	£24,800	£29,600	£34,500
2 adult household	£27,500	£32,300	£37,200	£42,000

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

We cover all Bristol postcodes, including Clifton, Bedminster, Redland, Kingswood, Filton, Horfield, and nearby towns like Yate, Thornbury, and Portishead.

If you’re unsure, contact us — we’ll confirm eligibility for your exact postcode.

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Save Money and Energy with Cavity Wall Insulation in Bristol

Yes — installing cavity wall insulation in your Bristol home can make a big difference to your energy bills.

Did you know that the average home loses heat in the following ways?

Windows: 10%

Walls: 35%

Roof: 25%

Floor: 15%

Draughts: 15%

By insulating your cavity walls, you can cut “wall heat loss” by around 70%, keeping more warmth inside where it belongs.

For a typical three-bedroom semi-detached house heated by mains gas, this can save roughly £400 per year on fuel costs (based on average energy usage). Homes using oil, LPG, coal, or electricity would save considerably more.

Cavity wall insulation doesn’t just save money — it also helps reduce condensation, improves comfort, and can lower carbon emissions by up to 3 tonnes per year, significantly shrinking your household’s carbon footprint.

The UK Government recognises cavity wall insulation as “the most effective energy-saving measure that most households can install” and a key step towards cutting national carbon emissions.

According to the Energy Saving Trust:

• Detached homes can save up to £600 a year
• Semi-detached or terraced homes save £250–£400 annually

These savings start immediately and last for decades.

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Most Bristol homes built after 1920 are suitable if the walls are made of brick with an unfilled cavity.

We offer a free home survey to confirm wall type, structure, and eligibility, etc.

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

The diagram above is a cavity wall.

The brickwork pattern in the diagram shows only long, rectangular bricks and no alternating short ends. It’s a cavity wall. But to be sure, book our free property survey — we’ll confirm everything for you.

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

We use high-performance polystyrene bead insulation, approved under UK Building Regulations. It is safe, fire-resistant, and designed to last a lifetime.

We exclusively use “SuperBead” polystyrene beads for cavity wall insulation, not mineral fibre options like “RockWool.”

Here’s a 6-minute video demonstrating how cavity walls are insulated and explaining why “SuperBead” does not cause damp.

And here’s some technical data.

Polystyrene beads are a superior insulation material for cavity walls, though they are more expensive. “SuperBead” cavity wall insulation is certified for several important properties:

Thermal Efficiency: “SuperBead” boasts a thermal conductivity of 0.035, making it highly effective in retaining heat.
Water Resistance: It resists water transfer across the cavity, preventing dampness.
Condensation Control: Keeping internal walls warmer helps reduce the risk of condensation.
Fire Safety: “SuperBead” does not compromise the fire resistance of the walls.
Durability: It is long-lasting, rot-proof, and water-resistant, remaining effective throughout the building’s lifetime.

Compared to fibre insulation, “SuperBead” is up to 20% more efficient. When installed, it’s blown into the cavity with an adhesive that sets within 20 minutes.

This process requires about 30% fewer and smaller holes than fibre insulation, creating a solid blanket of polystyrene that reduces heat loss by approximately 70%.

The polystyrene beads are rigorously tested, fire-resistant, and certified by the BBA for use in extreme conditions.

As part of the installation process, we conduct a Cavity Assessment Survey (CAS) to ensure your walls are suitable for insulation.

This is part of the improved quality control standards under the Great British Insulation Scheme (GBIS), formerly the free Cavity Wall Insulation Grant scheme.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Typically, 2–4 hours. It’s a clean, external process — no mess and no disruption inside your home.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Cavity Wall Insulation and Damp — Setting the Record Straight

According to the Cavity Insulation Guarantee Agency (CIGA), damp issues occur in fewer than 3 homes out of every 1,000 that have had cavity wall insulation installed.

Most of the problems historically associated with cavity wall insulation (CWI) stemmed from inappropriate materials being installed into unsuitable wall types — not from the insulation process itself.

From Rockwool to Modern Beads: How Materials Have Evolved

In the past, Rockwool was the main material used for cavity wall insulation across Bristol. Today, it has been replaced by modern polystyrene beads, which perform far better in preventing moisture penetration and heat loss.

Early installations using small white polystyrene beads (similar to those found in beanbags) sometimes caused damp problems due to their small size, low density, and poor water resistance.

Modern systems use larger, grey, water-repellent beads, often shaped like small coffee beans or mixed in different sizes to improve packing and airflow. These beads are impregnated with a water-resistant coating, providing a far superior barrier against moisture.

The Root Cause: Poor Surveys, Not the Insulation

Historically, most damp issues were caused by poor assessments rather than the insulation itself. Some installers, driven by door-to-door sales under earlier grant schemes, failed to carry out pre-installation surveys at all, resulting in insulation being fitted to properties that were never suitable.

Major Improvements in Quality Control

In April 2017, the British Board of Agrément (BBA) — the UK authority responsible for certifying that building materials are “fit for purpose” — took control of ensuring that unsuitable homes would no longer be insulated. This led to the creation of the Cavity Assessment Surveillance Scheme (CASS), a rigorous quality-assurance system designed to prevent future problems.

In October 2018, CIGA took over management of the CASS programme, strengthening oversight even further.

How the CASS Process Works

Under the CASS scheme, every property undergoes a comprehensive pre-installation survey, typically lasting around two hours.
This includes:

• Camera inspections inside the cavity
• Checks on wall condition, cavity depth, and construction type
• Assessment of gutters, downpipes, ventilation, and any rubble or obstructions inside the cavity

Leaking gutters or poor drainage are among the main external causes of dampness — and these are now carefully reviewed before any insulation is installed.

Once completed, the survey data and photographs are uploaded to CIGA’s central platform for audit.

• Every survey is desktop-audited by CIGA
• 1 in 10 properties receive an additional on-site inspection by a CIGA surveyor to double-check the original assessment

A New Era of Confidence

This level of quality control has virtually eliminated the risk of unsuitable homes being insulated and has greatly reduced the likelihood of damp problems occurring.

Before 2017, CIGA estimated that around 3 in 1,000 insulated homes might experience damp. With the CASS inspection system now in place, that number is expected to drop even further, giving homeowners complete peace of mind when installing cavity wall insulation in Bristol.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Cavity Wall Insulation Guarantee — Your 25-Year Peace of Mind

Yes — every cavity wall insulation installation in Bristol comes with a 25-year guarantee issued by the Cavity Insulation Guarantee Agency (CIGA).

CIGA provides independent protection for homeowners, covering both materials and workmanship for a full 25 years. This guarantee ensures that your insulation remains safe, effective, and reliable for decades to come.

To qualify for a CIGA guarantee, your property must first pass a Cavity Assessment Survey (CAS) — a detailed inspection confirming that your walls are suitable for insulation. Without a successful CAS survey and CIGA approval, a grant cannot be issued.

About the Cavity Insulation Guarantee Agency (CIGA)

CIGA was established in partnership with the UK Government’s Energy, Environment and Waste Directorate (part of the former DETR) to provide homeowners with a consistent, trustworthy guarantee for cavity wall insulation installations nationwide.

Independent research commissioned by the Department of the Environment, Transport and the Regions confirmed that cavity wall insulation is a highly reliable process, with defects being extremely rare.

If an issue does arise, CIGA has the expertise and systems in place to investigate and resolve it quickly. The introduction of the modern Cavity Assessment Survey (CAS) has further reduced potential risks by ensuring that only appropriate properties are insulated.

Quality Assurance You Can Trust

CIGA also manages the Cavity Wall Insulation Self-Certification Scheme (CWISC) in collaboration with the British Board of Agrément (BBA). This scheme guarantees that all work carried out by registered installers meets Building Regulations and maintains the highest standards of quality and safety.

With these safeguards in place, homeowners in Bristol can enjoy complete confidence that their free cavity wall insulation is both professionally installed and fully protected for the next 25 years.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Yes, but with your landlord’s consent. Landlords benefit too — cavity wall insulation boosts EPC ratings and makes their property more energy-efficient and valuable.

However, to qualify for a Great British Insulation Scheme grant, you will need to be in receipt of a qualifying benefit. See FAQ 3.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

No, unless your property is listed or in a conservation area. However, some local authorities insist that the cavities have to be insulated if the walls are to be rendered or rerendered.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Yes! If you meet the scheme’s criteria, the entire cost — from survey to installation — is fully funded through the Great British Insulation Scheme. No hidden charges, no catches.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

It’s quick and simple:

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Yes — improving your EPC rating makes your home more energy-efficient and attractive to buyers or tenants. It’s one of the best low-cost upgrades available.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Definitely. By keeping more heat inside your home, you’ll burn less fuel and reduce your carbon footprint, supporting Bristol’s net-zero 2030 goals.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Cavity wall insulation lasts for the lifetime of your home. It needs no maintenance and continues to save you money every year. It comes with a 25-year guarantee.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Our survey can check existing insulation to ensure it’s still performing properly. If it’s old, damp, or incomplete, we could replace it. However, there is no funding for “Extraction and Refill”, and it’s not cheap. An average semi-detached house would cost about £3,000 to extract and fill.

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol

Getting started is easy!

To find out if you qualify, or to book a free no-obligation survey

or call us on 0800 8 10 10 60 or 07960 and speak to one of our cavity wall experts.

FAQs Cavity Wall Insulation in Bristol