Keep the Heat In. Keep the Bills Down.

You may be entitled to a full or partial grant for cavity wall insulation.

Cavity Wall Insulation is one of the most cost-effective ways to improve your home’s energy efficiency — with minimal disruption and immediate impact.

Rear exterior view of a brick house featuring a modern paved patio area, a wooden pergola with seating, glass French doors, and a small brick outbuilding under a clear blue sky.

Why choose Cavity Wall Insulation?

Instant Comfort
Keeps heat inside and cold air out
Energy Savings
Cut heating costs by up to 25–30% beads
Eco-Friendly
Reduce carbon emissions and improve your BER
A BlueBuild installer using specialized equipment to inject cavity wall insulation into a property.
A side view of a dark grey BlueBuild flatbed service truck driving on a rural road, with two technicians visible in the cab against a backdrop of rolling green hills and a cloudy blue sky.
A BlueBuild technician wearing a protective respirator mask, safety glasses, red ear defenders, and a high-visibility vest operating a heavy-duty Hilti rotary hammer drill to core an openings in a concrete block wall.

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
A smiling woman wearing a headset takes notes with a pen while looking toward her open laptop at a wooden desk in a bright office environment.

Northern Ireland Grants for Cavity Wall Insulation

Homeowners in Northern Ireland may be eligible for support through a range of government-backed energy efficiency schemes — helping to reduce or even fully cover the cost of installation.

Available support can include:

  • NISEP (Northern Ireland Sustainable Energy Programme) – including fully funded options for eligible households
  • Affordable Warmth Scheme for lower-income homes
  • Potential support through local council or energy supplier initiatives

Grant levels and eligibility vary depending on your property type, household income, and current energy efficiency rating.

Our team will:

Assess your eligibility during your free survey
Guide you through the most suitable funding options
Handle the application process where applicable

👉 Find out if you qualify for fully funded insulation on our Residential Grants page.

Hear from Our Customers

  • Exceptional quality. Let me tell you how we found out about Blue Build (it certainly wasn't the usual way... thanks, or should I say no thanks, to my wife Anne). We have a south-facing roof at the back of our house, and we always thought that we should get solar, being south-facing, but were always put off by the cost (this was about 10 yrs ago). Then about 2 yrs ago, my wife, who is a keen ukulele player, happened to be out at her weekly band practice when she was talking to a friend about solar energy. This friend said to her that she had it and she had got a local firm that did it. She was a teacher and had taught the guy that sold it to her. Anyway, my wife came home and told me about this friend having solar and all the benefits of making money from the extra energy going back to the grid. I asked her who the installers and she said, "I don't remember, but it had a colour in it's name, and this lady had taught the owner" I replied, "Was it Blue Build?" and she enthusiastically replied, "Yes, that's the company. So we headed off to find Blue Build, who had moved from Balloo Industrial Estate to Quarry Heights, Newtownards. We spoke to a young guy who was very helpful, and he asked me who had recommended them to us, and I went into this story about a teacher who had possibly taught him, and that wife couldn't remember the installers other than a colour in their name. He looked a bit puzzled but came out to our house in Bangor within an hour to do a survey, and because they had been 13 yrs in business, gave us a quote for 13 solar panels, an inverter and a Duracell Battery. It was much cheaper than we had been quoted some 10 yrs previous (obviously technology had moved on and things where now much cheaper). They came and did a fantasic job, really neat and tidy and in the first year we received nearly £500 from Power NI because of the surplus going back to the grid. Also our electricity bills dropped from about £150 -£200 a quarter to about £50 for a 2000 sq ft house with 3 reception rooms and 4 bedrooms, kitchen and utility room and a double garage. Now here is the bit in the story that always gets me. I happened to be at one my wifes Ukelel gigs and I got talking to my wifes friends husband who had supposely recommended Blue Build. I said, "Thanks to your wife we got Blue Build to install our Solar sytem and they were fabulous from the price to the installation.....it was fabulous, so thanks for recommending them to us" He looked puzzled and said, " We didn't get Blue Build to install our Solar System". "What?" I said, "you didn't?" but my wife said there was a colour in the name, and he laughed and said, "No, there was no colour in the name". I just couldn't believe it my wife had made that mistake about the colour in the name, but in saying that, I am delighted we went with Blue Build as they are so, so helpful and nothing is a bother to them, and we have a fantastic system that saves us money every single day and it works without doing anything to it. I recently bought an EV car and am using the solar to help charge the car. The other night I charged the car from 2% to 78% for about £9, and that gives me about 270 miles. I would thoroughly recommend Blue Build for Solar Installation; they are absolutely brilliant
    Harry Kerr
  • We decided we wanted to get a solar system for the house. So first things first did a bit of research online on local solar companies I had three different companies give me a quote. One of these companies was Bluebuild. First I had a call from a lovely guy called Ian Millar he came to have a look round my property then he sent me through a full layout of what would take place should I go with them. After speaking to the other two companies I found Ian to make the most sense plus I wanted to go with panels on the front and back of the house but Ian insisted that I ONLY needed 12 on the front. This in its self proved that they weren’t money grabbers they told you the truth this is VERY hard to get in this day and age. Anyway I decided that bluebuild was the guys to go with and I’m so glad I did … what a genuine top company I would have given them ten stars… from the guys with the scaffolding arrived to the full install was carried out all totally professional people and all nice guys to boot. Saving on my electric already…I am a very sceptical person and find it hard to trust anyone honestly if your thinking about going down the solar route please don’t go anywhere else this company has to be the best in the six counties. Thanks again Bluebuild👍👍😃👍👍
    Alan McClintock
  • Bluebuild Energy recently insulated my house and upgraded my heating system. I would highly recommend Jason and his team. They were so efficient and professional. 5 stars from me.
    Martin Byrne
  • From the very beginning, we have had excellent communication with Bluebuild. Vassily and his team are very hard workers and Fionn did a great job in the attic. Jason ensured that everything was reinstated perfectly. We are delighted with the job....... Michael and Jenny, Co. Wicklow
    Michael Purcell
  • From start to finish,the team were all excellent. All work done was completed to a really high standard. Jason went above and beyond in ensuring that the work was done quickly and professionally. I cannot recommend Bluebird enough.
    Theresa McLoughlin
Google Reviews
Rated 4.7 out of 5 stars on over 100+ reviews

Accreditations & Partnerships

soltherm logo
Dublin City Council logo
sustainable energy authority of Ireland logo
nsai logo
bba logo
iwa logo
msc logo
terraco logo
utility regulator logo
constructionline logo
Installation Assurance Authority Logo
NQA certification badges for ISO 9001 Quality Management, ISO 14001 Environmental Management, and ISO 45001 Health and Safety Management.

​​Your trusted partner in energy efficiency

​​Your trusted partner in energy efficiency

Cavity Landing Form