Martyn's Law and your fire strategy: invacuation is not evacuation

The Terrorism (Protection of Premises) Act 2025 — Martyn's Law — is expected to come into force in spring 2027. Its standard tier requires procedures for four things: evacuation, invacuation, lockdown and communication.

Two of those point people in the opposite direction to a fire alarm, and that is the part a responsible person has to resolve rather than file.

The two tiers, and where the line falls

• –Standard tier: premises where it is reasonable to expect 200 to 799 individuals — staff included — to be present at the same time.
• –Enhanced tier: 800 or more, on the same counting basis. Qualifying events of 800 or more with controlled entry are treated the same way.
• –Childcare, primary, secondary and further education premises, and places of worship, stay in the standard tier even above 800. Higher education does not get that exception.

Staff counting towards the figure is the detail most people miss on a first read, and it is the one that moves borderline premises across the line.

The four responses, and where they collide

• –Evacuation: get people out. The fire procedure already does this, and the building is designed for it.
• –Invacuation: bring people in, or keep them in, because the threat is outside. The opposite instruction, delivered to the same people, in the same building.
• –Lockdown: secure the building against entry — which means working against doors and routes designed to let people out quickly.
• –Communication: tell people which of the three is happening, in a building where one sound has meant one thing for decades.

A building with a single alarm tone and a single evacuation strategy has one message available and now needs three. That is a design question before it is a procedures question, and it is the reason to start on this before spring 2027 rather than after.

What not to do to the fire strategy

The obvious temptation is to bolt the new responses onto the fire procedure. It is worth being careful about that, for a reason that has nothing to do with terrorism.

• –Fire escape routes and final exits are protected for a reason, and anything that makes them harder to use in a fire has made the building less safe in the far more likely event.
• –Lockdown measures that impede egress are a fire safety problem whatever they achieve for security, and the Fire Safety Order duty does not bend to accommodate them.
• –A single alarm that now means three different things is worse than one that means one, unless the communication is genuinely unambiguous.
• –Staff who have practised one response for years will default to it under stress. A procedure that exists only on paper will not change that.

The resolution is usually separate signals and separate drills rather than a combined procedure — and whatever is decided belongs in the fire safety record alongside the reasoning, because the next responsible person will need to know why the building works the way it does.

Where the duties sit relative to each other

Martyn's Law does not amend the Fire Safety Order. They are separate duties, with separate regulators — the SIA for one, the fire and rescue authority for the other — landing on premises that are often the same premises and often the same person.

In a building with more than one responsible person, that is worth mapping now: who holds which duty, and who decides when the two point different ways.

• –Establish whether each premises is in scope at all, and at which tier.
• –Audit your drill and evacuation records for what has actually been practised, not what is written down.
• –Decide how the three responses are signalled differently, and test that people can tell them apart.
• –Record the decision and the reasoning, including anything you chose not to do because it would have compromised escape.
• –Keep the two duties' records distinguishable. A single folder marked emergency procedures helps nobody when two regulators ask different questions.