What is BS EN 50131?

BS EN 50131 is the European and British standard series for intruder and hold-up alarm systems, covering system requirements, equipment and installation. It defines the four security grades used to match a system to the risk at a property, and compliance with it is expected for any system intended to have police response.

It is a series rather than a single document, with parts covering the system as a whole, individual detector types, control equipment and power supplies.

For a buyer, the practical content of BS EN 50131 is the grading system, and the fact that a compliant installation must be designed against a documented risk assessment rather than assembled from whatever was in the van.

You should expect an installer to tell you which grade they are designing to and why, and to leave you with documentation. If a quote does not mention a grade, ask.