What is Cavity Wall Insulation?
Many Irish homes built from the 1930s onward were constructed with two external walls and a gap (cavity) between them.
Cavity wall insulation fills that gap with high-performance insulating material, helping your home retain heat, lower heating costs, and feel noticeably warmer — often immediately.
The result? Warmer walls, reduced heating bills, and a more comfortable home — all in a day’s work.
*Please note we install Cavity Insulation only when required as part of a complete External Wall Insulation upgrade for your home and not as a stand alone measure.
Why choose Cavity Wall Insulation?
Is My Home Suitable?
We recommend a free survey to confirm suitability, but generally:
- Homes built from the 1930s and early 2000s
- Walls with unfilled cavity gaps (typically 50mm+)
- External walls in good structural condition
- Detached, semi-detached, or end-of-terrace houses
Homes with solid walls (pre-1970s) may be better suited to External Wall Insulation.
Our Installation Process
Our expert installation is fast, clean, and typically completed in just one day.
Here’s how it works:
- We carry out a detailed wall assessment to confirm suitability
- Small, discreet holes are drilled in the external wall
- High-performance insulation beads are injected to fully fill the cavity
- All drill points are carefully sealed to match the original finish
Extraction & Removal of Old Insulation (When Required)
Not all homes have clean, empty cavities. Some contain old, poorly performing, or failed insulation — such as mineral wool, or degraded foam.
Before we install new insulation, our team can fully assess and remove unsuitable material when needed. This ensures:
- The cavity is clean and unobstructed
- New insulation fills the space evenly and effectively
- Moisture issues caused by old insulation are eliminated
- You receive maximum thermal performance from your upgrade
Our extraction service includes:
If your home has cold patches, damp spots, or previously failed insulation, extraction may be the first step in restoring comfort and efficiency.
SEAI Grants Available
The Sustainable Energy Authority of Ireland (SEAI) offers generous grants for homeowners
installing EWI:
BlueBuild will support you through the grant application process from start to finish.
Frequently Asked Questions on Insulation for your home
We’ve answered some common questions to help you with any concerns
Not at all. It’s a low-impact process with no interior work needed. All holes are sealed to match your wall.
Installed correctly, cavity wall insulation can last for the life of the building — 30+ years.
That’s what our free survey is for. We’ll carry out wall inspections and even use a borescope if needed.
Yes — and it’s highly recommended for best results and full grant benefit.
Our Installation Process
To check wall type and insulation potential
We prepare and submit your application
Using small drill points
Insulation fills the cavity wall completely
Wall finish restored to match original
Most installations completed in 4–6 hours.
Hear from Our Customers
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I recently had my house wrapped by BlueBuild, and the entire experience was smooth from start to finish. My first point of contact was David, the project coordinator, who organised everything efficiently and kept the process running seamlessly. Different members of the team came by throughout the project to get things moving, and everyone was professional, friendly, and considerate. They always called in advance to make sure I was at home before arriving. Although this type of work can be quite messy, I was pleasantly surprised by how clean they kept both the inside and outside of the house throughout the job. They made a real effort to minimise disruption at every stage. Once all the preparation work was completed, John and his team arrived to carry out the wrapping. There were five people working incredibly hard, even on a Saturday, and their work ethic was outstanding. They worked nonstop and always made sure the areas were left as clean and tidy as possible before leaving each evening, even when they were returning the next day. On the final day, the team went above and beyond, cleaning the windows, blowing away dust, wiping down surfaces, and even covering the skip with plastic to ensure nothing could blow out before collection. The attention to detail and professionalism really stood out to me. I’m absolutely delighted with the finished result and the smooth overall experience. I would definitely use BlueBuild again, and I’m already speaking with them about solar panels. Without hesitation, I’ll be choosing the same company for that project too.
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Very happy with the work that was done on the house. The improvement it has already it brilliant. The men doing the work were so efficient and friendly too.
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Thanks for all the great work done by the team ,they kept the place very tidy and worked long days to get it finished for me . My project manager was a great help always able to take my call . Thanks to the team in the back office also regards Edward
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Very professional team, clean work delivered. Friendly and helpful team providing a super service. Highly recommended 👌
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I've just had external wall insulation to my house and while it's an excellent job, most of the credit goes to Jason Roe, project manager. Nothing was a problem to him. He was so considerate and attentive. He made it all happen without a hitch. I would definitely recommend Bluebuild 100%
Ready to Keep the Heat Where It Belongs?
Get professional, affordable insulation installed quickly — with grant support included.
• SEAI-Registered Contractor
• Fully Insured & Certified Installers
• 13+ Years’ Experience
• Customer Satisfaction Guarantee