What airbrick position tells you about the void
Airbricks are usually set low in the external wall, roughly level with the underside of the ground floor joists, and their spacing gives a rough guide to how well the void beneath is ventilated. Terraces that have had render or insulation added to the outside wall sometimes end up with airbricks accidentally covered, which is easy to miss from inside the house.
- Count and locate airbricks from outside before assuming the void is adequately vented
- External works such as raised patios or paths are a common cause of accidentally blocked vents
- A survey from inside alone can miss an airbrick that has been sealed from the outside



