Why cavity wall insulation is important

When booking a snagging inspection with HomeSnag, you will be prompted whether to have your cavity wall insulation checked. The importance of this is to consider that fact that a lot of customers booking us post-completion are experiencing heat loss, and as per the recent example shown above, it is often due to poorly insulated walls.
Cavity wall insulation in a traditional block and brick build is not there to provide 'warmth' to insulate the house in the same way there is wool insulation in most lofts; it is actually to prevent air circulation. This is why some builders use other materials such as Polystyrene balls, as the objective is to blow in material that will prevent air circulation as efficiently as possible.
The installers should strategically drill and blow in insulation in various areas of the house, but of course this always doesn't happen as efficiently as needs be. We drill test holes and use a borescope camera to inspect areas in several parts of the house and often find a severe lack of insulation as shown above.
One common area for the builder to miss is insulating above a garage, leaving customers wondering why their bedroom above the garage is colder than the rest...