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Fire alarm installation in St Albans, to BS 5839-1.
Conventional and addressable fire alarm systems for offices, schools, warehouses and communal areas, designed around your building and its fire risk assessment, installed and serviced by our own electricians.
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SEG designs, installs, commissions and services fire detection and fire alarm systems for offices, shops, warehouses, schools, care and supported housing, communal areas and public buildings across St Albans and Hertfordshire. Systems are installed by our own NICEIC-approved electricians to BS 5839-1:2025, designed around the building and its fire risk assessment rather than a standard package.
Fire alarm installation in St Albans for commercial buildings
The system a small office needs is very different from a school, a warehouse or a block of flats with communal areas. We install for:
- Offices and business centres
- Shops, restaurants and hospitality premises
- Warehouses and industrial units
- Schools, churches and community buildings
- Care homes, sheltered and supported housing
- Communal areas in blocks of flats and HMOs
- Public-sector buildings
- Construction sites and refurbishments
Where a building has several uses, complicated escape routes or people who need help to leave, the design matters even more, and we will say so.
Conventional or addressable fire alarm systems
Every system has a control and indicating panel, manual call points, automatic detectors where the category needs them (smoke, heat or multi-sensor), and sounders, with visual alarm devices where people may not hear a sounder.
- Conventional systems split the building into zones. The panel shows which zone has activated. A good fit for smaller, simpler premises.
- Addressable systems identify each detector and call point individually, so you know exactly where the alarm started. Better for larger buildings, multi-occupancy sites and anywhere a quick, precise response matters.
We specify what the building needs, not the most complicated system on the market.
Fire alarm categories under BS 5839-1
- Category M: manual system. People raise the alarm at call points.
- Category L (L1 to L5): automatic detection to protect life, from whole-building coverage (L1) to specific risks (L5).
- Category P (P1 and P2): automatic detection to protect property.
The category comes from the fire risk assessment and the building’s fire strategy. It should never be chosen on price alone. Fire alarms in homes are covered by BS 5839-6, which is what our Aico alarm service is designed to.
How we work
- Requirements. We go through the premises, the fire risk assessment and what the system has to do.
- Survey. We look at the layout, how the building is used, access and any existing alarm or electrical equipment.
- Design and specification. Panel, detectors, call points, sounders, cable routes and any interfaces, such as door release or access control.
- Installation. Our own electricians install the system, working around your business and in occupied buildings where needed.
- Commissioning and handover. Every device is tested. You get the certificates, a logbook and a walk-through of how to use the panel and do the weekly test.
- Servicing. Periodic inspection and servicing, normally at intervals of no more than six months, with records kept for you.
Your fire safety duties as a business
Under the Regulatory Reform (Fire Safety) Order 2005, the responsible person for a non-domestic building, usually the employer, owner, landlord or managing agent, must carry out and review a fire risk assessment and put suitable fire precautions in place. A fire alarm is often a central part of that, but it does not replace escape routes, emergency lighting, procedures or training. If your fire risk assessment has left you with actions, our FRA upgrade works service closes them out.
Fire alarm questions we’re asked
Does every business need a fire alarm system?
It depends on the premises and the fire risk assessment. A small shop may need little more than manual call points and sounders; a school, care home or multi-storey building needs automatic detection designed to a category. The responsible person for the building must have a fire risk assessment, and that sets what is needed.
What is the difference between a conventional and an addressable fire alarm?
A conventional system divides the building into zones, so the panel tells you which zone has activated. An addressable system identifies each individual detector or call point, so you know exactly which device has gone off. Addressable systems usually suit larger or more complex buildings; conventional systems can be the right answer for smaller premises.
What does BS 5839-1 cover?
BS 5839-1 is the British Standard code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in non-domestic premises. The current edition is BS 5839-1:2025. Fire alarms in homes are covered by BS 5839-6 instead.
What do the categories M, L and P mean?
Category M systems rely on people raising the alarm at manual call points. Category L systems (L1 to L5) use automatic detection to protect life, with different levels of coverage. Category P systems (P1 and P2) are designed to protect property. The fire risk assessment and the building’s fire strategy decide which category is required.
Can you connect a fire alarm to door access or other systems?
Yes, where the design calls for it. Fire alarms commonly release magnetic door holders and access-controlled doors, and can signal to other building systems. Any interface has to be part of the agreed specification and tested at commissioning.
Do fire alarms need ongoing testing and servicing?
Yes. BS 5839-1 recommends a weekly call point test by the building’s own staff and periodic inspection and servicing by a competent contractor, normally at intervals of no more than six months. We can provide the servicing and keep the records.
Is this the same as your Aico alarm service?
No. This page covers fire alarm systems for commercial and other non-domestic buildings, with a control panel. For mains-powered interlinked smoke, heat and carbon monoxide alarms in homes and rented properties, see our Aico alarms page.
Last updated 10 October 2026.
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