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Intruder Alarm Systems
Commercial Intruder Alarm Systems
Intruder detection is the part of a security estate most likely to have been specified by an insurer, installed a decade ago, and never revisited. It is also the part most likely to be quietly failing: sensors masked by racking that moved, zones permanently isolated because they kept false-alarming, and a signalling path nobody has tested since commissioning.
Evolution designs, installs and maintains commercial intruder and hold-up alarm systems to the current British and European standards, and integrates them with the rest of your security estate rather than leaving them isolated.
Intruder Alarm System Design and Integration
Risk assessment and system design to PD 6662:2017 and the BS EN 50131 series, including BS EN 50131-1:2006+A3:2020
Grading of systems from Grade 1 to Grade 4 against assessed risk and insurer requirement
Hold-up alarm design for cash handling, reception and lone-worker positions
Confirmed activation design to BS 8243:2021 where police response is required
Alarm transmission system design to BS EN 50136-1:2012+A1:2018, single path and dual path, configured for connection to your chosen Alarm Receiving Centre
Integration with access control, so setting and unsetting follows real occupancy
Integration with video surveillance for alarm verification
False alarm investigation and remediation in line with BS 8473:2018
Commissioning, maintenance and remote support to BS 9263:2016, with visit frequency matched to grade and notification option
Choosing the Right Intruder Alarm Grade
BS EN 50131 defines four grades based on the capability of the intruder the system is expected to resist.
- Grade 1: low risk. Opportunist intruder with no knowledge of alarm systems and limited tools. Rarely appropriate for commercial premises.
- Grade 2: low to medium risk. Intruder with limited knowledge of alarm systems and a general range of tools. Common for small commercial sites.
- Grade 3: medium to high risk. Intruder conversant with alarm systems, using a comprehensive range of tools and portable electronic equipment. The usual baseline for commercial and industrial premises of any value.
- Grade 4: high risk. Intruder with the resource and capability to plan an intrusion in detail, where security takes precedence over all other factors. Applied to high-value, high-consequence and critical national infrastructure sites.
The grade determines equipment specification, detection coverage, tamper protection, standby power duration, signalling resilience and maintenance frequency. Specifying below the assessed risk to save cost usually surfaces at claim stage rather than at intrusion.
Police Response And Confirmed Activations
A Unique Reference Number, which entitles a system to police response, requires the system to generate confirmed activations under BS 8243:2021. Confirmation means two independent detection events, so a single sensor triggering does not on its own summon a response.
Systems that generate excessive false alarms lose their URN. Regaining it is a process, not a phone call. BS 8473:2018 sets out the code of practice for managing false alarms, and most of the problems we are called to investigate come down to a small number of causes: detector placement against changed site use, environmental interference, poor entry route design, or a system configured for a building that no longer operates the way it did when it was commissioned.
We investigate and fix the cause rather than isolating the zone.
Intruder Detection as Part of an Integrated Security System
An intruder alarm running as a standalone island is a wasted asset. Integrated properly it becomes considerably more useful:
The system sets and unsets against actual occupancy, so the last person out does not need to remember, and the site is never left unset because someone forgot
An activation pulls the associated camera view for verification, so whoever responds is looking at the event rather than guessing
With building management
Activations can trigger lighting, lock down zones, or notify a facilities response
Our Intruder Detection Technology and Platforms
Evolution delivers intruder detection primarily within integrated security platforms rather than as standalone panel installations. In practice that means intruder detection designed and configured inside the platform already managing access control on the site, so that detection, access and video operate under one system rather than three.
Where a standalone or hybrid arrangement is the right answer, we specify against the requirement and the applicable grade.
Global Intruder Alarm Integration in Practice
Global software company, new office, integrated with systems on two continents
A global software company was relocating its UK office and needed the new site to match the physical security standard already running across its international estate.
The requirement was consistency rather than capability. The company already had access control and intruder detection in the United States, and the new office had to join that estate rather than sit alongside it as a standalone installation. Evolution was recommended as one of a small number of companies in the UK and Ireland able to source, configure and integrate the specific systems already deployed across the client’s global estate.
The design combined a compatible access controller, card readers, an intruder alarm and multi-path monitoring. Where existing hardware could be reused, Evolution said so, which reduced cost without reducing performance. Integration with the building’s existing fire alarm system was managed alongside the incumbent fire contractor, with Evolution overseeing sub-contractor activity throughout.
The relocation schedule was tight, and quoting and ordering inside the programme was what kept it on track. When custom configurations and off-site integrations added complexity mid-project, the scope absorbed it without moving the completion date.
The client’s systems engineer noted that Evolution met the immediate requirement and stayed flexible when further changes were needed. The completed installation lets the company administer and monitor access control across every site from one platform, with no additional system needed in Belfast.
FAQs About Intruder Alarm Systems
PD 6662:2017 is the scheme document setting out how the European standards are applied in the UK, and remains the current edition. It draws on the BS EN 50131 series for system and component requirements, BS 8243:2021 where confirmed activations are needed for police response, and BS EN 50136 for alarm transmission. Commissioning, maintenance and remote support are covered by BS 9263:2016, and false alarm management by BS 8473:2018.
It depends on assessed risk, not on building size. Grade 2 suits lower-risk commercial premises; Grade 3 is the common baseline for commercial and industrial sites with meaningful asset value; Grade 4 applies to high-consequence environments. Your insurer will often state a minimum. A risk assessment determines the answer properly.
Police response requires a Unique Reference Number, issued against a system that generates confirmed activations in line with BS 8243:2021 and is connected to an approved Alarm Receiving Centre. Excessive false alarms can result in the URN being withdrawn.
It depends on grade and notification option. Grade 2 systems typically require one maintenance visit per year, or two where certain notification options apply. Grade 3 and above typically require two visits per year, or one site visit plus one remote system check, in line with BS 9263:2016.
Most commonly because the building changed and the system did not. Racking moved into a detector's field, a new air handling unit created movement, an entry route no longer matches how people enter, or a detector is at the end of its service life. Isolating the zone hides the problem. We diagnose the cause.
Yes. We take over third-party systems regularly. We will survey it, tell you what standard it currently meets, and be direct about anything that needs remediation before we can certify it.