How often should I undertake a room integrity test?

British Standards BS EN15004 states that any enclosure protected by a gaseous fire suppression system requires a room integrity test when it is commissioned and annually thereafter. It should also be retested if any works are carried out to the building envelope, this can include works such as the installation of a new door or seals and/or new cables, pipe work or ductwork. Studies reveal that the predominant cause of failure of gaseous extinguishing systems is poor room sealing. It is also found that the room integrity performance reduces with time; this is usually due to changes in construction the additions of cabling or services, or simply by natural movement of the enclosures envelope.