Fire Alarm Installation London | BS 5839 Compliant

Most of the fire alarm calls we take start with a letter — from a council, a managing agent, an insurer or a solicitor — asking for something the owner did not know they needed. So before anything else, here is what the law actually requires, because it is narrower than most quotes imply and it differs depending on what sort of property you have.

What the law actually requires

So for a straightforward rented house or flat, compliance is achievable with battery alarms. We nearly always recommend going further, to a mains-powered interlinked Grade D1 system, for three practical reasons: interlinked alarms sound together so people on a different floor hear it, a sealed ten-year battery backup cannot be removed by a tenant who is tired of a chirp, and it is the standard a council, an insurer or a buyer’s solicitor expects to see. Our page on smoke alarm regulations for London landlords goes through the duty in detail, and smoke alarm installation covers the fitting work.

HMOs: LACORS and the licence conditions

Houses in multiple occupation are a different matter. The Management Regulations require the owner to keep all means of escape free from obstruction and the fire-fighting equipment and alarms in good order, and licence conditions commonly specify a detection standard. The reference point inspectors use is the LACORS national fire safety guidance for existing housing, which grades the required system by the size and layout of the building and the risk — typically a Grade D interlinked system with detection in the escape route and in each bedroom for a small shared house, moving up to a Grade A panel system with a mixed detection category in larger or higher-risk buildings, bedsit-style conversions, and anything above a certain number of storeys.

Because that scales with the building, nobody can quote an HMO system honestly off a phone call. We look at the storeys, the escape route, the door arrangement and how the units are let, then specify. Licensing schemes in London boroughs change from time to time and vary by street — check your council’s current scheme for your address rather than relying on what applied last year. See HMO EICRs for the inspection side of the same building.

Commercial premises: the Fire Safety Order

In any non-domestic premises the Regulatory Reform (Fire Safety) Order 2005 puts the duty on a “responsible person” — usually the employer, occupier or owner. That duty is to carry out a fire risk assessment and then put in place appropriate fire precautions, including means of giving warning in case of fire. The Order does not list a system for you; the risk assessment decides what the building needs, and the technical standard for designing and installing it is BS 5839-1.

That is why a competent commercial quote names a category, not just a grade: an L1 system covers the whole building for life protection, L2 adds detection in defined high-risk rooms to the escape routes, L3 protects the escape routes so people can get out, L4 covers circulation areas only, L5 is a bespoke engineered solution for a specific risk, P1 and P2 are for property protection, and M is a manual system of call points and sounders with no automatic detection. If a quote does not state the category, you cannot tell whether it meets your risk assessment, and neither can your insurer.

For multi-occupied residential buildings there is a further layer — the Fire Safety Act 2021 and the Fire Safety (England) Regulations 2022 brought in duties about the structure, external walls and flat entrance doors, and information-sharing with the fire service. Those sit with the building’s responsible person rather than with the individual leaseholder, but they shape what managing agents now ask us for in communal areas.

Fire alarm grades explained

“Grade” describes the equipment and its power supply. “Category” describes how much of the building is covered. You need both to specify a system, and they come from the two parts of BS 5839 — Part 6 for domestic premises, Part 1 for everything else.

Grade F — battery only

Stand-alone alarms powered by a battery. F1 has a sealed long-life battery, F2 a replaceable one. Legal in a rented home in England if there is one on every storey and they work. Not interlinked, so an alarm going off in the kitchen does not wake anyone upstairs. We fit these only where there is genuinely no practical route for cable and the client understands the limitation.

Grade D — mains-powered with battery backup

The normal answer for a house or flat. D1 has a tamper-proof, non-removable backup battery; D2 has a replaceable one. Interlinked, so every alarm sounds together — by cable, or by a radio-interlinked base where chasing cable through a finished ceiling cannot be justified. For rented property, D1 interlinked is the specification we recommend and the one councils and agents expect.

Grade C — detectors and sounders with central control

A mains system with separate sounders and some central control and indicating equipment, but short of a full BS 5839-1 panel. It is the usual middle answer for a converted house in multiple occupation where a full Grade A panel would be disproportionate but Grade D is not enough.

Grade A — a full BS 5839-1 system

Control and indicating panel, dedicated circuit, monitored cabling, manual call points, automatic detection and sounders, with a 24-hour standby supply and the whole installation designed, installed, commissioned and certified to BS 5839-1. Conventional zoned panels for smaller buildings; addressable panels where you need to know which device has operated. Required in most commercial premises of any size, in larger HMOs, and wherever a fire risk assessment calls for it.

What fire alarm work costs in London

These are our labour and certification charges. Panels, detectors, call points, sounders and cable are itemised separately on the quote at trade cost, so you can see exactly what you are paying for. Our minimum charge is one hour at the standard rate: £90 + VAT, £108 inc VAT. Nothing is priced below that.

Job	Labour only, ex VAT	Notes
Minimum charge / first hour	£90	£108 inc VAT. Applies to any attendance.
Standard hourly rate thereafter	£90/hr	Out of hours £60 + VAT per half hour.
Single alarm point added to an existing interlinked system	from £90	Subject to the £108 inc VAT minimum.
Grade D1 interlinked system, 1–2 bed flat (2–3 points)	from £180	Smoke in the hall, heat in the kitchen.
Grade D1 interlinked system, 2-storey house (3–4 points)	from £250	Plus a CO alarm where a fixed appliance needs one.
Grade D1 or Grade C system, 3-storey shared house (5–8 points)	from £420	Specified after a look at the escape route.
CO alarm, fitted alongside other work	from £90	One per room with a fixed combustion appliance.
Grade A panel system, commercial	quoted after survey	Priced on category, zones and device count — we will not guess it over the phone.
Inspection and certificate on an existing system	from £150	Functional test of every device, written report.
Six-monthly service visit, Grade A system	from £150	Per visit, logbook completed.
Fault-finding on an alarm that will not reset	£90/hr	Most faults are found inside the first hour.

Emergency lighting is a separate system with its own standard and its own certificate — prices are on the emergency lighting certificate page. If you need the electrical installation inspected at the same time, doing both in one visit saves a second attendance: see EICR cost London 2026 and commercial EICR costs.

Maintenance, testing and the logbook

A fire alarm system is only worth what its last test proves. For a Grade A system BS 5839-1 recommends a weekly user test of a manual call point — a different one each week, so every zone gets exercised over time — and servicing by a competent person at intervals not exceeding six months, with the results written in the logbook kept on the premises. For domestic Grade D systems the user test is weekly too, with the detectors cleaned and function-tested at least annually.

Our service visits include a functional test of every detector, call point and sounder, a check of the standby supply and battery condition, a look at anything that has changed in the building since the system was designed — a new partition, a new kitchen, a room put to a different use — and a written report with the logbook entries completed. Insurers and licensing officers ask for that paper trail, and it is the thing most often missing when we take over a system from somebody else.

What we find in London properties

A few patterns come up again and again across the North and East London stock we work in:

• Alarms on a plug-in supply or a lighting circuit switched off at the wall. A Grade D system needs a permanent supply; if the circuit can be switched off, it is not one.
• Mixed makes interlinked together. Different manufacturers’ alarms generally will not interlink reliably even when the terminals look the same. We replace the set rather than hope.
• Heat detectors in bathrooms and smoke detectors in kitchens — the wrong device in the wrong room, which produces either false alarms or no alarm.
• Converted houses with a system designed for the old layout. A house split into flats needs detection in the common escape route, which the original domestic system never had.
• Commercial panels in permanent fault with the sounders disabled because nobody could find the fault. That is a building with no means of warning, however good the panel looked when it was fitted.
• No logbook, no commissioning certificate, no zone plan. Without those an inspector has nothing to accept, whatever is on the wall.

Common questions

Do I legally need interlinked mains alarms in a rented flat in England?

Not strictly. The 2015 Regulations as amended require a working smoke alarm on every storey used as living accommodation and a CO alarm in any such room with a fixed combustion appliance; they do not specify mains power or interlinking in England. We still recommend Grade D1 interlinked, because it is what councils, agents, insurers and buyers’ solicitors expect and because it actually wakes people on another floor.

Does a gas hob mean I need a carbon monoxide alarm?

No — gas cookers and hobs are specifically excluded from the duty under the regulations. A boiler, gas fire, wood burner or oil heater in a room used as living accommodation does trigger it. Fitting one near a hob anyway does no harm, but it is not the thing the law is asking for.

How often does a commercial fire alarm need servicing?

BS 5839-1 recommends servicing by a competent person at intervals not exceeding six months, alongside a weekly user test of a call point recorded in the logbook. Insurers commonly make the six-monthly service a condition of cover.

Can you certify a system somebody else installed?

Yes. We inspect and test what is there, report on it against the relevant part of BS 5839, and tell you plainly what it would take to bring it up to standard. What we will not do is sign a certificate for a design we cannot verify — if there is no zone plan or commissioning record for a Grade A system, that goes in the report.

What is the difference between a fire alarm and an EICR?

An EICR inspects the fixed electrical installation — circuits, board, earthing, bonding. A fire alarm inspection tests the detection and warning system. A rented property generally needs both, on different cycles, and they are separate certificates. See landlord EICRs for the five-year duty.

Which areas do you cover?

We are based at Ten 87 Studios on Markfield Road in Tottenham N15 and work across Haringey, Hackney, Islington, Enfield, Waltham Forest, Camden, Barnet, Newham and Tower Hamlets, plus central EC and W1 where the job suits. The full list is on our service areas page.

NICEIC approved, Part P registered, working to BS 7671 18th Edition and BS 5839, fully insured. Certificates and logbook entries issued on completion. More reading: our electrical guides · smoke alarm regulations for landlords · emergency lighting certificates · PAT testing · all our electrical services.