A zone plan is the drawing beside the panel that turns a zone number into a place. Without it the panel tells an attending firefighter that zone four is in alarm and nothing else. With a good one, the same person knows in seconds which floor, which wing and which end of the building to go to, which is the entire reason the panel is zoned at all.
What the plan has to show
A simple orientated plan of the building with the zones marked and numbered to match the panel exactly, the position of the panel itself, the main entrance and any repeater panels. It should be legible from standing distance in poor light by somebody who has never been in the building before. Detail that helps nobody at three in the morning is detail that gets in the way.
Where it goes
Adjacent to the control panel, and adjacent to any repeater panel, because a repeater is there precisely so somebody can read the system from a different entrance. If the fire service attends at a different door from the one your panel is behind, that is a conversation to have with the brigade rather than a reason to leave the plan where it is.
Keeping it true
Zone plans go wrong quietly. A partition moves, a zone is split during a refurbishment, a repeater is added, and the drawing on the wall is now describing a building that no longer exists. An out of date plan is actively dangerous because it will be trusted. Checking the plan against the panel is a five minute job that belongs in the periodic inspection.
The log book beside it
The zone plan and the log book belong together with the panel keys, because they are the three things somebody needs at once. The log book records the weekly tests, the service visits, every actual alarm and every false alarm with what caused it. False alarm records are the most useful part: a zone that keeps crying wolf is a design or environment problem the service visit can fix.
Questions people ask about fire alarm zone plan
Is a zone plan legally required?
The Fire Safety Order requires appropriate arrangements and information rather than naming a zone plan. In practice a zoned system without a plan cannot be used as intended, and enforcing officers expect to see one.
Does a single zone system need a plan?
A plan showing the building, the panel and the extent of the single zone is still useful to an attending crew, and it costs almost nothing. It also stops the system being quietly split into two zones without anybody documenting it.
Who updates the zone plan after building work?
The responsible person owns it. In practice the contractor doing the alteration should provide an updated drawing, and it is worth making that an explicit condition of the order rather than an assumption.