Warmer rooms, lower heat loss, and a more comfortable home, installed by a PAS 2030 certified team and registered with a 25-year guarantee. Free, no-obligation technical inspection & quotation.
Get Started
Submit your details to speak with one of our representatives about cavity wall insulation or to arrange your free, no-obligation inspection.
We Inspect First. We'll check whether cavity wall insulation is right for your property. If we find underlying issues, we'll explain what needs to be remediated first, so your home can be made suitable before any insulation work is considered.
Certified, Registered, Insurance-Backed
The Problem
Did you know that most of the heat lost from an average UK home escapes through the walls? Cavity wall insulation acts like a cosy jacket for your home, helping keep it warmer in winter and cooler in summer, while saving you money on energy bills.
Heat Loss
Of Heat Can Be Lost Through Walls
But It's Also One Of The Areas You Can Do Something About
If your cavity walls are unfilled, poorly filled, or affected by moisture, your home may lose heat faster than it should. A professional inspection helps confirm what is happening and whether insulation, remedial work, or ventilation improvements are the right next step.
Average UK dual-fuel bills now sit at £1,641 - more than double 2016's £700, with rises to around £1,840 forecast for late 2026.
How Cavity Wall Insulation Helps
Filling your cavity walls can save the typical UK home between £110 and £395 a year on heating - keeping more cash in your pocket every winter.
Cavity wall insulation helps your home hold onto warmth, so rooms feel more comfortable even after the heating turns off.
How Cavity Wall Insulation Helps
Suitable insulation can reduce cold spots, support a more even room temperature, and help your home feel warmer through the colder months.
What Happens Next
From a free technical inspection through to installation day and your completion pack, we keep each step clear so you know what we are checking, what happens on site, and what paperwork you receive afterwards.
See Our Process
What We Often See On Site
We've visited many homes where certain rooms never seem to stay warm for long, even when the heating is working. Sometimes the issue is linked to missing insulation, older materials, patchy coverage, or external walls that lose warmth quickly in exposed weather. These patterns are often noticed first as cold walls, slow-heating rooms, condensation patches, or draughty-feeling areas near outside walls.
Below are the patterns we see most often across South Wales before we recommend bonded bead insulation.
Heat escapes quickly through unfilled cavities, which results in Uninsulated cavity walls even after you've turned the heating up.
Common Signs
Why It Matters
Bonded bead fills the cavity evenly where suitable so emitters regain control without chasing boiler upgrades.
Warm indoor air meets colder surfaces near external walls. Uninsulated cavity walls make those surfaces colder for longer.
Common Signs
Why It Matters
Better insulated surfaces lift temperatures whilst we flag ventilation tweaks whenever inspections suggest they're needed.
Older properties are often ruled out too quickly. We check the cavity properly so you know whether modern bonded bead insulation may be suitable for your home.
Common Signs
Why It Matters
Many older properties were previously ruled out for cavity wall insulation because the cavity was considered too small. Modern bonded bead systems may now be suitable for some narrow cavities, but only where the wall condition, exposure, and cavity width are right. That is why we inspect first before recommending any installation.
Some homes have one wall or room that always seems harder to keep warm, especially side walls, gable ends, or rooms facing open weather. Homeowners often notice that these areas feel colder, take longer to heat up, or are more prone to condensation after wet or windy weather.
Common Signs
Why It Matters
If one side of the property is more exposed, we need to check the wall and cavity properly before recommending insulation. The wall may still be suitable, but exposure, moisture, and external condition all need to be considered first.
Before any insulation is installed, we make sure your property is suitable for cavity wall insulation. Our team checks the condition of the walls, plans the correct installation approach, and provides clear evidence once everything is finished.
Step 01 Of 04
Our friendly surveyor will thoroughly inspect all elevations (sides) of your property to determine if our bonded bead insulation system is the best choice for you. They will use a specialised camera to take photos during the inspection, ensuring that the cavity void is clean, clear, and suitable for installation. This information will be communicated to our office to prepare your quotation.
What We Confirm
If the survey flags anything, we can usually put it right before we insulate. We'll make that clear in your quote.
We'll start by checking whether your property is suitable for cavity wall insulation. From there, you'll receive clear advice, a works plan, and guidance on what happens next.
Roughly One Working Day
Most cavity installs are aimed at a single day on site, subject to property size and weather.
Mostly From Outside
The bulk of the work is carried out externally; internal access, if required, is agreed at survey.
Clear Access Helps
Please leave gates, paths, and working areas reachable so we can move kit and materials safely.
Parking For The Crew
Nearby parking makes unloading equipment quicker and saves time on the day.
Pets And Children
Keep them away from active work areas while we are on site so everyone stays safe.
Book an inspection and we’ll tell you straight if it’s the right move, and what happens next.
Book A Free Quotation
Included after installation
Your Completion Pack
Once your EPS Bonded Bead Insulation System has been installed, we provide clear paperwork describing the system, the guarantee details, and any aftercare information you need to keep for your records.
This gives you a clear record of your EPS Bonded Bead Insulation System, useful information for future home improvements, and peace of mind that the installation has been properly documented.
Confirmation of the EPS Bonded Bead Insulation System installed at your property.
Details of the guarantee provided with your EPS Bonded Bead Insulation System, where applicable.
Clear information about the cover linked to your EPS Bonded Bead Insulation System.
Photos or records confirming the work has been completed and checked.
Simple guidance on what to expect after installation and who to contact if you have any questions.
Provided where required, depending on the type of work and scheme requirements.
Your completion pack helps you keep a clear record of your EPS Bonded Bead Insulation System. It can be useful if you sell, remortgage, arrange future home improvements, or need to check your guarantee details later.
Exposed elevations, bridging debris, unresolved damp pathways, ventilation shortfalls or failed historic insulation can rule out cavity fill until remediation happens. CRS handles damp remediation, ventilation and extraction programmes, so our surveyors prioritise an honest sequence rather than a quick sale.
Bonded-bead cavity insulation
We recommend EPS bonded-bead insulation. It is designed to spread evenly through the cavity, reduce heat loss and support reliable performance over time. Find out more below.
EPS bonded beads are blown into the cavity to build an even layer across the agreed areas.
Cavity insulation can trim heat loss through external walls so rooms feel warmer in colder weather.
The EPS bonded bead system limits unwanted water tracking yet stays vapour open, meaning moisture vapour can still move through the wall naturally.
Work is usually carried out from outside through small holes along the mortar joints, then sealed and left tidy once the fill is complete.
A small number of properties may still need minimal internal access or finishing where your survey identifies it; your installer will confirm what applies before work begins.
Satisfied this is the right system for your home? Book a free inspection and we will confirm suitability before any work is scheduled.
Book A Free QuotationWhy CRS
CRS Energy is a Wales-based retrofit specialist. We measure first, recommend honestly, and only install when the property is genuinely suitable.
Family Founded 2018
10,000+ Installations
Started with one van in South Wales. Today a fully in-house team of surveyors, installers and retrofit specialists.
Employee Owned
EOT Since 2024
Owned by the people who do the work, so accountability for quality and aftercare stays with the team on site.
Independently Audited
PAS 2030, TrustMark
Every install governed by PAS 2030, registered with TrustMark, and backed by insurance-backed guarantees.
We're proud to help South Wales homeowners protect the property they live in every day. Here is what some of our customers have shared after working with us.
We had cavity wall insulation done which has made a big difference to our house. Our rooms were cold and we had some mould in corners of the rooms. Since having it done there hasn't been any. House warms up quicker and stays warmer longer. So glad we had it done and it was quick and easy. CRS were lovely and I would recommend them to anyone.
This company carried out the work on our house for a Welsh government grant scheme, the work was carried out between July and September for a new boiler and internal wall and cavity wall insulation. Every one of the workers in the different teams, including the plumbers, electricians, insulation team, carpenters, plasterers, and the painter were all very polite, friendly and respectful of our property. We would highly recommend them.
I cannot praise this company too highly. From first contact to completion of the work the whole experience was perfect. People turned up when they were supposed to and were all friendly, good-humoured and respectful, and they knew what they were doing. All three teams that carried out the work were well coordinated and efficient. And they all cleared up after them! Great coordination between the office and the survey and work teams.
Every review above is published on our public Google or Trustpilot profile, or was sent to us directly by the customer, as marked on each card. View On Google or View On Trustpilot.
Transparent Pricing
No guesswork. No off-the-shelf packages. We measure, assess, and quote based on your home's actual floor area and construction type - so you only pay for what's needed.
Floor area (m²)
The primary measure - total heated floor space determines the scope of works.
Insulation type
Cavity wall, loft, internal wall, room-in-roof - each has a different material and labour rate.
Construction type
Cavity, solid brick, timber frame - affects product choice and install method.
How It Works
Get in touch and we'll arrange a visit. We'll measure up, assess your property and give you a clear, itemised quote - calculated on your actual floor area.
Still unsure? Book a free inspection and we will confirm whether bonded-bead cavity insulation is appropriate for your home.
Book A Free QuotationSpeak to a surveyor directly - no sales pitch, no obligation.
£ Finance
Monthly payment options are available for cavity wall insulation installations, provided through our partner Ideal4Finance, with 0% finance available on selected agreements.
Choose a term that suits your household, see the full agreement before you commit, and pay a fixed monthly repayment for the length of the term.
Finance is a regulated credit agreement arranged through Ideal4Finance. You apply directly, the agreement is subject to status, and you'll see the full terms, including the total amount repayable, before you sign anything.
Spread the cost over an agreed term with a fixed monthly repayment.
Every agreement shows the complete cost and term before you commit.
Finance is a payment option, not a requirement. You can pay for your installation without it.
Enter your postcode below to check your eligibility and explore finance options for your installation.
Complete the form and we'll arrange your free, no-obligation inspection. Or call 01656 334698.
Complete Remedial Solutions (CRS) Ltd, trading as CRS Energy, is an Introducer Appointed Representative of Ideal Sales Solutions Ltd, t/a Ideal4Finance. Ideal Sales Solutions Ltd is a credit broker and not a lender (FRN 703401). Finance available subject to status. The rate offered is always provisional and will depend upon your personal circumstances, the loan amount and the term.
There are risks involved in taking out a loan and you should ensure you can make all payments on time and in full; failure to do so can lead to financial difficulties and have a negative impact on your credit score.
