BS EN 50131 (There are a number of parts to this standard which are relevant to the particular aspect of the Alarm system, from communication to the detector for example)

Alarm systems. Intrusion and hold-up systems.

PD 6662:2017

Scheme for the application of European Standards for intrusion and hold-up alarm systems.

Further advice relating to Alarms and SBD Installer and ARC Schemes can be accessed by clicking HERE