AS 1670.4
EWIS Block Plans
An EWIS block plan documents the Emergency Warning and Intercommunication System in a building. It shows speaker zones, warden intercom phone (WIP) locations, alert/evacuate zone sequences, and the relationship between detection zones and EWIS response — essential for emergency wardens and fire brigade operations.
What is an EWIS block plan?
An EWIS block plan is a schematic showing the layout and zoning of a building's Emergency Warning and Intercommunication System. It documents speaker zones, WIP locations, the alert/evacuate sequence and how the system interfaces with fire detection. It enables wardens and fire crews to understand and manage evacuation communications.
Why do you need one?
AS 1670.4 requires EWIS documentation that enables system operation and testing. Buildings with EWIS must have clear documentation of zone layout and evacuation sequences. Fire brigades use this documentation when they take control of the system during an emergency.
What AS 1670.4 requires
The block plan should show: speaker zone boundaries and identification, WIP locations and zone allocation, alert/evacuate sequencing (which zones alert vs. evacuate on each trigger), interface with fire detection zones, manual override controls, and any staged evacuation logic.
Common problems we solve
EWIS documentation is often the most neglected of all fire safety documentation. Common issues include: no EWIS block plan at all, plans that don't reflect current zone programming, missing cause-and-effect documentation for alert/evacuate sequences, and plans not updated after tenancy changes or floor reconfigurations.
Frequently Asked Questions
What is the difference between alert and evacuate?
In a staged evacuation system, "alert" notifies occupants of a potential emergency (beep tone), while "evacuate" gives the instruction to leave (whoop tone + voice message). The block plan documents which zones receive which signal in each scenario.
Do you document the cause-and-effect for EWIS?
Yes. We document the programmed alert/evacuate sequences — which detection zone triggers which EWIS response and in what order.
Is EWIS documentation needed for the Annual Fire Safety Statement?
Yes. If your building has an EWIS, its maintenance and documentation are covered by the fire safety schedule and must be current for the AFSS.