Have your cavity walls filled with insulation
If your outer walls have a cavity, filling it takes one to two days, needs no permit and usually pays for itself in three to five years.
Flanders · Subject to change
Sources checked on · next check by . Check the source before you act.
Many walls built after the Second World War have a cavity between two layers of brick. Insulation is injected into it from outside, without changing the facade. A test drill in a joint tells you a lot: if the drill breaks through after about 10 cm, there is a cavity. Such walls are usually at least 24 cm thick.
An installer then checks the cavity with a camera. It must be at least 5 cm wide and not full of mortar or brick debris. Insulating is not advisable with frost damage, cracks, an outer layer that blocks vapour (such as glazed brick or some paints), or a facade exposed to driving rain.
You can choose any contractor, who stays liable for the work for 10 years. Premiums require a contractor on the official list of certified installers, so check the current conditions first.
Details
| Impact | Not rated · The cited sources don't give a size for this saving, so we don't guess. How we rate impact |
|---|---|
| Payback time | About 3 to 5 years · according to Vlaamse overheid (vlaanderen.be). Depends on energy prices and your home. |
| Estimated saving | The Flemish government says the investment is usually earned back in 3 to 5 years. (confidence: medium) |
| Who acts | You (owner) |
| Needs landlord's agreement | No |
| Type | Action |
Do this together with
Sources
- Muurisolatie (in Dutch) · Vlaamse overheid (vlaanderen.be) (official source) · checked on