This part of IEC62820 series gives guidelines for planning, installation, commissioning, operation and maintenance of Building Intercom Systems (BIS), for use in security applications. The different technical requirements for BIS are specified in IEC62820‑1‑1 and IEC62820‑1‑2 . The objectives of this document are to: provide a framework to assist system integrators, installers, consultant engineers and system owners in establishing their requirements; assist specifiers and system owners in determining the appropriate equipment required for a given application.