Professional cavity wall insulation

A cavity wall consists of an inner and outer wall separated by a cavity. In many homes this space is uninsulated or only partly insulated.

Nu-Isoleren fills a suitable cavity with EPS beads injected from the exterior, improving insulation without opening internal walls.

Cavity wall insulation is mainly intended for existing homes with an empty or insufficiently insulated cavity. Because the material is injected from the outside, the internal finish can usually remain untouched and no usable floor space is lost.

Searches such as insulate a cavity wall or retrofit cavity wall insulation refer to the same principle: filling the existing gap between the inner and outer leaves in a controlled way with a suitable insulation material.

Correctly installed cavity wall insulation can reduce heat loss and improve indoor comfort.

Besides reducing heat loss, many households notice the comfort improvement: internal wall surfaces feel less cold and temperature differences are reduced. The outside appearance is largely preserved because drilling takes place in the mortar joints and the openings are made good afterwards.

Not every cavity can be insulated without inspection. We assess width, condition, brickwork, pointing, contamination and moisture.

Existing insulation or debris may need to be removed first.

Not every cavity can be filled immediately. We check the available width, possible rubble or mortar bridging, the condition of the pointing and whether old insulation is already present. In some homes the cavity first needs to be cleaned or previous insulation removed.

We use high-quality EPS beads from Isomo nv in Kortrijk-Heule, installed with a bonding agent to create a stable insulation layer.

Read more on our EPS insulation page.

Nu-Isoleren uses high-quality EPS beads from Isomo nv in Kortrijk-Heule for this application. The beads spread through the available cavity and are injected together with a bonding agent to create a stable insulation layer. More technical information is available on our EPS insulation page.

Nu-Isoleren works as a recognised installer with an officially ATG-certified system installed under defined technical conditions.

An ATG approval relates to a technically assessed system rather than only the name of an insulation material. It sets conditions for the product, substrate and installation. Proper cavity assessment and installation according to the prescribed method are therefore part of the complete system.

The exact process depends on the property.

After the inspection we determine the drilling pattern so the beads can spread evenly throughout the wall. Filling is carried out systematically in zones. The drill holes are then closed with matching mortar and the treated areas are checked.

The price depends on wall area, cavity width, accessibility, façade condition and preparation. A property-specific quotation is therefore more reliable than a fixed generic price.

The cost of cavity wall insulation depends mainly on wall area, accessibility, cavity width and condition and any preparatory work. Contamination or damaged pointing can add extra work. A universal price per square metre is therefore only indicative; a free quotation gives a price based on the actual property.

Depending on region and circumstances, grants may be available. See our grants section.

Grant conditions and amounts can change and differ by region and project. We therefore avoid fixed amounts on this service page. Our central grants page brings together the relevant regional information and conditions.

View cavity wall insulation projects completed by Nu-Isoleren.

Answers about suitability, material, pricing and installation.