Cavity wall insulation: explore your options

Cavity wall insulation is an effective way to make a home more energy-efficient. It involves filling the space between the inner and outer walls (known as the cavity) with insulating material. This helps keep your home warmer in winter and cooler in summer. Insulating cavity walls prevents moisture problems, reduces your energy bills, and improves overall living comfort. The investment is relatively low, with costs typically ranging between €20 and €37 per square meter. In addition, you may be eligible for subsidies through the ISDE scheme, often resulting in a payback period of just 3 to 5 years. Our advisors always assess whether your home is suitable for cavity wall insulation, whether it was built in 1920, between 1920 and 1975, or more recently.

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A conversation is always completely non-binding.

We always apply a minimum price of €950.

“Recently had cavity wall insulation installed by De Vries Insulation. I used their clear website and calculator, which recommended EPS HR++ beads. Afterwards, I had an on-site consultation with Jaap and got a very good impression. After approving the quote, the insulation was installed within two weeks. Ready for winter!”

“Exceptionally friendly and polite team who insulated the cavity walls of my home. Afterwards, they cleaned everything up neatly. Top!”

“After comparing several companies, De Vries stood out thanks to Jeroen’s clear advice and guidance on subsidies. The team completed roof, floor, and wall insulation in one day. Friendly, professional, and everything left clean and tidy. Very satisfied, especially given the competitive price.”

“A very pleasant company! De Vries Insulation has insulated our floor and cavity walls. A really friendly and hardworking team. Jeroen provides clear advice and thinks along with you, communication with Laura is smooth and efficient, and the team is friendly and works neatly. Fair pricing, which is also important. No need to look further, just go for it.”

Cavity wall insulation is the process of filling the air gap between the inner and outer walls of your home with insulating material, such as glass wool or EPS beads. This helps prevent heat loss and keeps cold air out.

How does cavity wall insulation work?

The process involves three simple steps:

Step 1. Small holes are drilled into the exterior wall.
Step 2. The cavity is filled with insulation material.
Step 3. The holes are neatly sealed to finish the job.

You could save up to 25% on your energy bills. For a typical terraced home, that’s around €500 to €800 per year. Actual savings will vary depending on the insulation material and the size of your cavity wall.

Yes, in 2026 you can receive a subsidy for cavity wall insulation through the ISDE scheme. On average, you’ll receive €6 to €8 per square metre of insulated exterior wall. If you combine this measure with, for example, floor insulation or roof insulation, the subsidy can increase to up to 30% of the total costs.

The best material depends on the width of the cavity, the condition of the façade, and your desired insulation performance. EPS beads are lightweight and water-repellent, while glass wool offers excellent sound insulation. A professional, certified insulation company (such as De Vries Insulation) can advise you on the most suitable material for your specific situation.

The cost of cavity wall insulation typically ranges between €15 and €30 per m², depending on the insulation material, the type of property, and how accessible the walls are. Thanks to subsidies and savings on your energy bills, the investment is often recouped within 3 to 5 years.

Installing cavity wall insulation typically takes just one day. A team drills small holes in the mortar joints, fills the cavity with insulation material, and then restores the façade. Disruption is minimal, and your home will feel noticeably warmer (or cooler in summer) right away.

Not every home is suitable. We check whether the cavity is wide enough and whether it’s free from debris or mortar residues. We also assess potential issues such as moisture problems or the presence of bats in the cavity.

Homes built between 1920 and 1975 often have cavity walls without insulation, making them ideal for retrofit insulation. It’s important that the cavity is clean and free from moisture issues. A specialist from De Vries Insulation can assess this in advance using an endoscopic inspection.

Cavity wall retrofit insulation involves adding to or replacing the existing insulation in the cavity with more modern and efficient materials. Although the initial investment may seem high, upgrading your cavity wall insulation can lead to significant long-term savings.