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Cavity wall insulation is a simple and cost-effective way of retaining heat in your home and
saving money on your energy bills.
Adding insulation to your cavity wall can prevent up to a third of your home’s heat from
escaping, saving you up to £225 a year on heating costs.
Cavity walls were not a common feature in most homes until the early 1930s, so knowing when your
house was built is a good indicator. If your house was built after 1930, it is likely that your
home has cavity walls.
If you are unsure when your house was built, follow our guide to find out if you have cavity
walls.
If you think your home has a cavity wall, you could be eligible for insulation to be added to
your home. Properties built from the 1990s onwards will most likely already have cavity wall
insulation.

Even if your property has some insulation in it, you could still benefit from a top-up. Most new
houses are built with just enough insulation to meet the building regulations and are often
compatible for a top-up.
Your home will usually be suitable for cavity wall insulation if:
- Walls currently have unfilled cavities
- Cavities are at least 50mm in width
- Brickwork is in general good condition.
Installing cavity wall insulation
Cavity wall insulation takes up to half a day to install, and in most cases can be completed
through the external walls only. Your installation expert from Wise Energy will drill small
holes at intervals across the outside wall to access the cavity.
Using specialist equipment, insulation is then inserted into the wall. Once the whole wall has
been filled, your installer will refill the holes in the wall, leaving your property with no
visible changes.