CROSS-UK has issued a critical Safety Alert titled “Smoke vents rendered inoperable by building work.” This alert is rated Red – the highest level on CROSS’s traffic light system – and is the first Red Alert issued since 2022.

This Alert draws attention to the safety risks associated with preventing the operation of smoke vents, in particular Automatic Opening Vents (AOVs), by construction work on existing buildings.

AOVs are provided as part of a fire safety smoke control system. In the event of a fire, an inoperable smoke vent poses a significant hazard. If smoke cannot be released from the building, it could hamper the escape of occupants and the ability of the fire and rescue service to fight a fire.

In many cases, AOVs can be indistinguishable from standard windows. This may lead to their inadvertent obstruction.

As part of its confidential reporting system, CROSS-UK has received several reports of AOVs being made inoperable by building work, including when façade materials are being replaced.

An AOV might easily be rendered inoperable by a scaffold pole, temporary masking, the storage of materials, or adjustments to cladding.

The SCA supports the recommendation to provide permanent, but discrete, signage on AOVs.

The full alert can be viewed here