Lockdown alert systems for venues, offices and schools
A lockdown alert system lets an authorised person trigger one clear instruction, in seconds, across every channel a building already has: voice alarm or PA, digital signage, desktops, phones and door control. Strive AV designs and integrates the lockdown messaging layer on top of a site's existing AV, IT and security systems, so the procedure in the Martyn's Law plan is something staff can actually execute.
Typical cost: £2,000 to £8,000 to add lockdown triggers and messaging to an existing voice alarm and signage estate on one site, £15,000 and up for a multi-site platform, plus £30 to £150 per site per month for mass notification subscriptions.
How a lockdown alert reaches staff and the public
No single channel reaches everyone. A lockdown alert system pushes the same instruction through every channel at once and records who acknowledged it.
| Channel | What it does in a lockdown | Design note |
|---|---|---|
| Voice alarm or PA | Repeats a recorded or live lockdown instruction in every occupied zone | Distinct from the fire alarm tone; message library pre-approved by the responsible person |
| Digital signage override | Interrupts every screen with the instruction and site-specific guidance | Priority message from the CMS or a hardware trigger; room panels included where the platform allows |
| Desktop and laptop pop-ups | Full-screen alert on managed PCs, with acknowledgement | Reaches staff with headphones on or away from speakers |
| Mobile push, SMS and email | Alerts staff, contractors and pre-registered contacts off site or in back-of-house areas | Mass notification gateway, subscription priced per site |
| Door control and beacons | Secures external doors, releases internal routes, drives visual beacons | Access control and lighting integration where fitted |
| CCTV and control room | Starts full-resolution recording and brings camera views to the control desk | Lets the incident lead confirm the trigger before an all-clear |
The signage and audio channels reuse the digital signage and commercial audio systems most premises already own, which is why a retrofit is usually the cheaper route.
Lockdown vs invacuation vs evacuation
Martyn's Law names evacuation, invacuation, lockdown and communication as the public protection procedures a premises must be able to carry out. Each one needs a different instruction and, ideally, a different signal.
| Procedure | Where people go | Typical threat | Signal |
|---|---|---|---|
| Evacuation | Out of the building to assembly points | Inside the building, routes out are safe | Fire alarm or voice alarm evacuation message |
| Invacuation | Inside, away from glazing, entrances and external walls | Outside or at the perimeter | Spoken invacuation instruction on voice alarm and signage |
| Lockdown | Stay in place, lock and barricade doors, silence devices | Inside or about to enter, movement is dangerous | Distinct lockdown alert on every channel, with an all-clear |
Lockdown alerting and Martyn's Law
The Terrorism (Protection of Premises) Act 2025 asks standard tier premises (200 to 799 people) to have procedures for evacuation, invacuation, lockdown and communication, and enhanced tier premises (800 or more) to document a public protection plan with measures that reduce vulnerability. Commencement is expected in spring 2027. The Act does not prescribe any product or technology; it asks for procedures that are reasonably practicable for the premises.
A lockdown alert system is how the lockdown and communication procedures become executable on the day, with a documented authority chain and a tested message. Start with our Martyn's Law compliance services or the free Martyn's Law assessment to find your tier.
Lockdown alert system FAQs
Q.What is a lockdown alert system?
A lockdown alert system is the integration that lets an authorised person trigger a clear, repeated lockdown instruction across every channel a site already has: voice alarm or PA, digital signage override, desktop pop-ups, mobile push and SMS, and where fitted, door controllers and beacons. Read the full lockdown alert system answer.
Q.How much does a lockdown alert system cost?
A single-site retrofit that reuses an existing voice alarm or PA and signage estate typically adds £2,000 to £8,000 for the trigger logic, message library and integration. A purpose-built platform across a multi-site estate with redundant trigger paths starts at £15,000, and mass notification subscriptions run £30 to £150 per site per month. Priced at survey because the existing systems decide most of it.
Q.What is the difference between lockdown, invacuation and evacuation?
Evacuation moves people out of the building, invacuation moves people inside and away from external glazing and entrances (a threat outside), and lockdown secures people in place behind locked doors (a threat inside or at the perimeter). Martyn's Law names all three alongside communication as the public protection procedures a premises must be able to carry out.
Q.Does a lockdown alert have to be a different sound from the fire alarm?
Yes in practice. A fire alarm tone tells people to leave, which is the wrong action in a lockdown, so the lockdown alert needs a distinct tone or, better, a spoken instruction repeated across voice alarm, signage and devices. Staff training then ties each signal to one procedure.
Q.Can our existing PA or voice alarm system carry lockdown messages?
Often, yes. Most addressable voice alarm and networked PA systems accept pre-recorded messages and a priority trigger input. The survey confirms whether the existing system has the message capacity, trigger inputs and zone coverage needed, and whether any change needs the building's fire and life-safety contractor to re-certify it.
