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The Essential, Easy Guide to the BS 5839-1: 2017

Smoke detector on wall and writing which says 'your easy guide to fire alarms and the BS 5839-1:2017'

Table of Contents

Last Updated on 21 September 2022.

The BS 5839 Part 1 is a code of practice for the design, installation, commissioning and maintenance of fire protection systems in commercial/non-domestic premises.

These “non-domestic premises” include offices, shops and shopping centres, hotels, public houses and restaurants, hospitals, schools, churches and care homes, among many others.

It also includes the communal areas of domestic premises, such as the hallways and corridors of a residential apartment block, as they affect multiple people within a common area where a fire could potentially take place.

Part 6, conversely, of the BS 5839 refers to domestic premises, such as a family home.

Here’s a quick video where our Founding Director Paul gives a brief low-down of BS 5839:

Is the BS 5839 the same as the Regulatory Reform (Fire Safety Order) 2005?

No – there’s a lot of confusion between the BS 5839 and the Fire Safety Order – they are not the same thing!

The Regulatory Reform (Fire Safety) Order 2005 is produced by the UK Government, and outlines legal regulations and responsibilities of Responsible Persons (e.g. business owners or designated premises managers).

If a fire takes place and you are investigated, your conduct against regulations set out by the Order will be analysed, and if found to be irregular or negligent then it will be considered a breach of this legislation.

The BS, on the other hand, stands for British Standards and is produced by the BSI Group, which sets a precedent and consensus for the quality of goods and services.

There are approximately 27,000 standards set out by this body; all of which lay out the specifications both manufacturers and installers/service providers must adhere to.

In short, the Fire Safety Order is primarily for you (the Responsible Person/building user) to tell you your legal responsibilities, and the BS 5839 is the compliance handbook for your installation and maintenance specialist to use to ensure what they’ve fitted is correctly installed.

Think of it like owning a car – you are legally responsible for ensuring you have an annual MOT, and for implementing any work needed if it fails before you can get it on the road again…But your mechanic will be responsible for ensuring they test your car against outlined measures and standards, which will dictate whether it passes or fails.

For example, the Fire Safety Order stipulates that you must have regular fire risk assessments of your premises to ensure adequate fire protection.

YOU, as the Responsible Person, must make sure this happens.

As a result of such an assessment, you might be told you need a specific category of fire alarm, and so you’ll instruct a fire alarm installer to design the system and put it in for you.

Fire alarm engineer working on a fire alarm panel

THEY will then have to ensure that what they install is compliant with the standards set out according to the British Standards.

However, if they don’t install something which is compliant with the BS, you (the Responsible Person) will be liable for this, even though you’ve done the right thing by having a fire risk assessment and then getting someone to install a fire alarm.

Click here to read more about Fire Risk Assessments.

How Do I Know My Installed System is Compliant?

I’m glad you asked! We’ve established the buck stops with the Responsible Person of a building.

Even though the average person doesn’t know (or need to know) the ins and outs of the BS 5839, they are still responsible for ensuring that what’s installed within their building meets the requirements laid out in that code.

Click here to learn more about the ‘Responsible Person’ and their duties.

The best way to know is to look out for companies which are third-party accredited.

This means that they are regularly audited for their quality management and technical capabilities, in line with the relevant standards.

For example, BAFE is the UK’s leading independent body for third-part certified fire protection companies.


If the company you’re using for your installation is BAFE certified, that means you can trust that they have been given an independent, unbiased seal of approval for the quality of their work and compliance with both industry and legal standards.

Plus, ensure they are backed up by the relevant insurances and references.

As the responsible person, you should satisfy yourself that the designer of your fire alarm system has appropriate design, installation and maintenance insurance.

Interestingly, the level of this is not set out in law and can vary, and your insurer may have a policy of what level of insurance you should expect.

Typically this would be £1m professional indemnity (for design alone) and £10m insurance for the Public and Products liability (for people as well as the design and installation of equipment installed).

This is not to be confused with the additional £10m employer’s liability insurance that all companies must have in place by law.

References are very important and is an important piece of verification for you as the responsible person.

Typically, you would want to be given details of previous clients of your chosen company so that you can call and speak with them directly; case studies are useful and it’s well worth looking at their online reviews such as Google and Trustpilot.

How is Fire Safety Policed?

When the Fire Brigade carries out spot checks and will review your fire risk assessment as well as  analysing the fire safety precautions within your premises, they will be looking at how you comply with the Fire Safety Order in your practices and how your premises complies with the British Standards regulations.

So, even though the Fire Safety Order and BS 5839 are not the same, they do work in tandem to provide a premises which is fully safe and legal.

The best way to be safe and legal is to ensure you (or your building’s ‘Responsible Person’) is familiar with their obligations as set out in the Regulatory Reform (Fire Safety) Order 2005 and to trust a BAFE accredited company to carry out any works relating to fire safety or fire protection, so you know that they work in line with British Standards and industry approved regulations.

Fire safety policing and investigations are becoming increasingly stringent following an increasing number of catastrophic events in recent years.

Grenfell, for instance, has instigated major talks across the fire industry and Government bodies, which could see fire safety legislation reform in the not-too-distant future.

But, for the time being, many investigations are retrospective and carried after a fire-related event, meaning that the damage is usually already done.

This entails an analysis of the building’s compliance with the BS 5839-1 (as well as the Responsible Person’s compliance with their responsibilities as per the Fire Safety Order).

Explaining the British Standard BS 5839-1…

This standard outlines fire alarm system categories, their relevant components, zone definitions, testing frequencies and procedures, and so on, for each step of the fire alarm installation process: design, installation, commissioning and maintenance.

There is A LOT of technical information in the BS 5839, so we’ve condensed some of the most notable points for you…

Designing and Installing a Fire Detection Alarm System:

There are three different categories of fire detection systems (L, M and P), and the type you’ll need to install will depend on the building type and composition, business nature, its physical size and footfall.

All fire alarms must meet the requirements of the BS 5839-1 according to its relevant category to be compliant.

The starting point for identifying which type of alarm system is right for your building is best decided by a professional with a Fire Risk Assessment.

In the risk assessor’s report they will identify all fire safety considerations, shortfalls and solutions, including the category of fire alarm which is best suited to protecting your building.

Once identified, the fire alarm designer can start the process of drawing up the system using building floor plans and a visual survey before moving onto installation.

Fire Alarm Installation Necessities

Click here to see the 8 steps you should undertake before buying a commercial fire alarm.

Category L Systems:

These systems are designed to protect life, hence ‘L’, and focus on safeguarding escape routes and areas considered as having a high fire risk. There are 5 categories of an ‘L’ type system:

Here’s a video which briefly explains what each of these ‘L’ types mean:

L5 – Bespoke Design

Building Example: Factory with Office and Server Room

An L5 system does not fall into any of the other four categories, and must be designed and installed based on specific requirements taking into account high risk factors, as outlined in the Fire Risk Assessment.

L4 – Escape Routes Only

Building Example: School

This means that automatic fire detection has been applied only to the escape routes, such as staircases and corridors, and not within any inner rooms.

L3 – Escape Routes AND the Room that Opens onto the Escape Route

Building Example: Office Block

This is one of the more common fire alarm systems and includes smoke detection on all escape routes with additional detection in all rooms leading directly onto the escape route.

L2 – Escape Routes, Rooms that Open onto Escape Routes, PLUS Inner Rooms Considered High Risk

Building Example: Factory

This is basically an L3 system with the added consideration of additional rooms that may not lead directly onto an escape route, but are considered high risk and therefore require fire detection.

This could be a room within a room, such as a server or boiler room.

L1 – Maximum Protection

Building Example: Care Home

This requires both manual call points and automatic fire detection installed throughout the premises with a detector in every room.

A room is defined as anything over 1m2, which is essentially as small as a big cupboard!

This is usually for buildings such as care homes, which are higher risk and may have vulnerable occupants.

Category M Systems

Building Example: One-room Kiosk

These are manual operation only systems which have manual call points on all exits and corridors where persons do not have more than 45m to walk before reaching a call point.

All ‘L’ systems start out as an ‘M’ system and then have the appropriate level of automatic fire detection coverage applied on top of that.

A system which is only an ‘M’ system, with no ‘L’ coverage added on, is usually for small buildings, sub-buildings or barely occupied buildings where shouting ‘fire’ would suffice to get everyone out and automatic fire detection is deemed unnecessary.

Category P Systems:

Building Example: Unmanned Warehouse

This category is designed purely for property protection and not life protection; as such, it’s rarer to see these types of systems as most buildings are occupied at any given time and therefore require life protection.

You’ll mostly see a Category ‘P’ system in unoccupied premises that are connected to an Alarm Receiving Centre (ARC) using alarm monitoring, which will immediately call the Fire Brigade to attend.

P1 – Whole Building

A P1 system installs automatic fire detection in all areas of the building to detect the sign of a fire as soon as possible.

P2 – Specific Parts of a Building

A P2 system doesn’t have automatic fire detection in all areas; only specific parts which are considered in a Fire Risk Assessment to be particularly high risk.

Once Your Installation is Complete!

Following the installation, the commissioning process involves testing the equipment, ensuring its functionality, and also comparing the recommendations from both the Fire Risk Assessment and the BS against what has been installed.

This is required to be carried out by a competent person.

Following commissioning, a formal handover of documentation can occur.

WFP Fire Alarm Engineer Demonstrating the use of a Fire Alarm to a customer

The end user/purchaser of the fire alarm system will be given their accurate drawings of the installed system, zone charts, operation and maintenance manuals, log books for ongoing maintenance, and any necessary training on the operation of the system.

Certificates are then provided, as well as O&Ms (Operations & Maintenance manuals), and the responsibility is handed over to the management of the building for day-to-day handling.

Completion Certificate for Fire Alarm

Ongoing Maintenance

The British Standard outlines the technical observations which must be adhered to for effective system composition, but also points out a number of manual observations and tests that must be done by a human being for routine maintenance and upkeep.

Take weekly testing, for example: the British Standard recommends that the fire alarm should be tested using a different manual call point each week, which should take place during normal working hours at the same time each week.

It also specifies that the weekly test should not exceed one minute so that the difference between a test and an actual fire alarm is clear to building inhabitants.

The British Standard also specifies that maintenance service visits should not exceed six months, otherwise the system will be non-compliant.

The nature of inspecting and testing a fire alarm system during a maintenance visit is outlined in detail in the BS 5839, and it is outlined that records of these visits, as well as weekly testing and any identified faults, are noted in the user’s log book (usually provided by the maintenance company) as written evidence of upkeep and compliance.

Similarly to the Fire Safety Order 2005, which specifies that each building/premises must have a designated ‘Responsible Person’ for fire safety, the British Standard recommends that “a single, named member of the premises management” should be appointed to “supervise all matters pertaining to the fire detection and fire alarm system”.

The ‘Responsible Person’ for the building and the person appointed responsible for the fire alarm may not be the same person.

For example, the ‘Responsible Person’ could be the building owner but the person in charge of the fire alarm could be the caretaker, who was appointed by the owner.

Updates in the BS 5839-1: 2017

The 2013 version of the BS 5839-1 identified and laid out the standardised procedures for the compliant design, installation, commissioning and maintenance of fire alarm systems.

The 2017 update of this British Standard included specific revisions of procedures which superseded the 2013 version, such as the need for all new manual call points to have a form of protective cover.

Manual Call Point on a wall with WFP sticker on it with the Number 1

This was to help prevent accidental or deliberate false activation by removing the easy access to the triggering break-glass feature of manual call points.

The update went onto distinguish and expand on the term ‘false alarms’ to include ‘unwanted alarms’ – and much more!

And there you have it! We hope you’ve benefited from reading this guide, but if you have any questions about any of the above or your fire safety responsibilities, please feel free to get in touch.

REMEMBER, the best way to know if you’re compliant with the British Standard is to have a Fire Risk Assessment.

Our team are here to help on 01277 724 653!

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20 thoughts on “The Essential, Easy Guide to the BS 5839-1: 2017”
  1. Thank you for the guide which is Very useful.
    I was wondering if you run any training courses concerning the installation and commissioning fire alarm systems.
    If you do so please email me all the details.
    Thank you for your cooperation.

    1. Hi Atif,

      Thank you for your comment, I’m glad you found it useful! We offer in-house training for our new engineers and existing to keep them under best practices, however the best place for accredited/certified courses is the FIA (it’s what we’re a member of also) which provides you with a Level 3 Qualification in the design, installation, commissioning and maintenance of fire alarm systems. There’s also the option to specialise and do an ‘Advanced Installer’ or ‘Advanced Commissioner’. I hope this helps!

      Kind regards,

      Verity Stone at WFP Fire & Security

    1. Hi Kim,

      Thank you for your comment! The number one thing you must make sure is that anyone carrying out electrical/fire safety work for you has appropriate accreditations. This means regardless of qualifications that they are independently audited. Qualifications and experience in the industry are good but vary and there is no minimum required, but should the work be found to be faulty/non-compliant/threatening to safety then it is on the Responsible Person’s head (i.e. who hired said company) on whether or not they took appropriate considerations for due diligence on the quality of the work being carried out. The appropriate accreditations for electrics is NICEIC and for fire alarm installers it is BAFE; both of which we do have. These also have websites with registers where you can check that your chosen provider has the accreditation they claim to have. I hope this helps!

      Kind regards,

      Verity (Head of Communications at WFP)

  2. Hi,
    We are a block of flats (9 storeys), and have always had a fire alarm system. After a recent fire alarm maintenance and repair work, we have been advised that we would need to do weekly fire alarm tests using manual call point. The manual call points are on the second floor, which used to be commercial premises but have recently been turned into residential. Is it possible to change the manual call point into automated systems and would it be compliant with the law?

    1. Hi Shyam,

      Thank you for your comment! Manual call points are typically not used in blocks of flats with a communal fire alarm; usually because of the potential for false alarms. The call points are there because of the commercial nature beforehand, and I suspect you’ve been told to use these to do weekly testing as the British Standards tell you that a weekly test is to be done with the use of triggering a manual call point. In terms of changing these to an automated system, i.e. detectors, to know whether this is compliant and before even tampering with the design and structure of your existing system you ought to have the stipulation officially in a Fire Risk Assessment. This change will also be established based on whether the building is deemed to need a stay put or a simultaneous evacuation strategy – which would be confirmed in the Fire Risk Assessment also. We can arrange this if you would like, so do reach out by calling 01277 724 653 if you need help here.

      Kind regards,

      Verity (Head of Comms at WFP)

  3. Other objectives, such as the protection against business interruption or protection of the environment are likely to be met by the recommendations of BS 5839 Part 1. [1] BS 5839 Part 1 [1] categorises fire alarm systems as: [2] “M” – manual system no automatic fire detectors so the building is fitted with call points and sounders , “L” – automatic systems intended for the protection of life, and “P” – automatic systems intended for the protection of property.

    1. Thanks for your comment, you are certainly right about the different categories. Are you having trouble with your particular fire alarm system or feeling as though there is not adequate detection meeting the protection requirements of your business or as per BS 5839-1? You should reach out to the installers/maintainers and/or the manufacturers (there should have been an O&M guide) provided upon installation to help you understand the system. If it’s an obsolete system like an EMS 5000 then you may need this upgraded as parts are no longer available for replacement, so if there was a fault it would most likely stay in fault. We are here to help if you need it – please call 01277 724 643 or email

  4. We are in the process of installing, smoke and heat detectors in a small residence property that consist of 3 flats, whereby 1 heat detector is installed on the inside of the front door of each flat from the communal alarms system, which consist of smoke detector on all 3 floors.
    my question is do we have to issue a commissioning certificate for each flat that has a heat detector installed even though they are linked with the communal smoke alarms.
    The contractor wants to issue 4 commissioning certificate at a cost per cert.
    I would very much appreciate your comment on this

    1. Hi Pat, from what you have described it is one system therefore one commissioning certificate will be adequate. However the contractor should be issuing a BS5839-1 design certificate, a BS5839-1 installation certificate and a hand over certificate. In addition to this if they are a third party accredited company, which they should be if they are installing a fire alarm system, then they should issue a BAFE SP203-1 (or LPS 1014) overall certificate in addition to the aforementioned. If the system is a radio based system you should be receiving the documented radio signal strengths and if wired an as-wired diagram. There should also be drawings showing the installation with device locations and numbers (depending on the system type) with sound level readings in addition to a zone chart mounted in a suitable frame adjacent to the fire alarm panel. Also don’t forget to organise your maintenance as this is required from installation in accordance with BS5839 part 1 2017, section 13.
      I hope that this helps and thank you for your question.

  5. Hi, I’ve always installed a ceiling void indicator when there is a Void detector installed, is there a regulation for this ?



    1. Hi Phil,

      Thank you for reading and your comment! In answer to your question, you only install remote indicators where you can’t see the led on the detector unless it’s addressable and has a correctly described in the text to tell the user the location. Generally we don’t install remote indicators on addressable systems because of that reason. It’s a common sense idea to have a ceiling void indicator (not specifically prescribed by BS) but if it’s addressable then this shouldn’t be needed.

      I hope this helps, Phil? If there’s anything we can do to help, please give us a call on 01277 724 653 or email!

      Kind regards,

      Verity on behalf of the WFP Team

  6. Our fire panel has 2 * 12v 18ah SLA batteries inside. At the last inspection the inspection company noted that these batteries were over 5 years old. The batteries are still producing appropriate power actually both were a bit over 13 volts very similar to what had been noted on previous maintenance visits so do not appear to be losing performance.

    Do we need to replace the batteries under the order or BS despite them performing to standard?
    If not how often should we check them to see they are still operating OK.
    If we do need to change them simply on age our maintenance company is quoting a cost for the batteries almost double the cost we could get the exact same batteries for ourselves. Installation is simply unscrewing the old batteries and rescrewing in the new batteries. Is this something we could do ourselves prior to the next maintenance visit or will this cause issues? We are a small charity and an extra £100 cost seems excessive when we are already paying for the maintenance visits.

    1. Thank you for your question.
      Five years is about the maximum lifespan of quality batteries for a fire alarm, the cheaper batteries only have a good working life of 3 years and it’s not easy to tell them apart unless you take the time to read the literature.
      The issue with batteries degrading isn’t the voltage (which can be easily measured on any multi-meter) it’s the current that they can deliver and this will mean that they won’t provide the designed stand-by, which is normally 24 hours and 30 minutes of sounders in full operation. Other times such as 48 & 72 hours could be required depending upon the circumstances.
      You’ll often find that batteries can be measured at the correct voltage even when they have degraded their ability to deliver power in a mains failure scenario.
      We use load testing devices to see what the battery is actually delivering, although it takes skill to use these and a lot of alarm companies just go on the age.
      As far as price is concerned there are considerations you should bear in mind.
      1. The alarm company is (should be) buying genuine spares designed to specifically for the job and should be disposing of the dead batteries. They will be paying delivery and disposal and will be fitting these for you and this which will affect the price you pay them.
      2. If they fail, presumably you’ll be able to put this back to the alarm company under warranty, which you won’t if you fit yourself.
      3. By fitting batteries you are accepting liability as the competent person and if there were issues involving the batteries you and the responsible person for the building will be liable. When you fit batteries you will be exposing mains voltage and must follow safe isolation procedures, you will also risk moving wires which could cause other faults on your system, the likelihood of which depends on the quality of initial installation. Any decent alarm company will have the skills and insurance for this.
      4. Modern alarm panels monitor the battery temperature and this will have to be refitted
      5. If you connect batteries back to front you may cause a spark and will damage the control panel, at the very least you’ll blow a fuse and modern panels use micro-fuses which you may not have at your building
      6. Good quality batteries should give you 4-5 years and therefore the cost is at least 1/4 per year in real terms
      You could ask for a maintenance price that includes batteries, we offer that service if required.
      One last thing to bear in mind is that a fire panel with faulty batteries will be non-compliant with the standards and it’s our advice that this is rectified immediately as effectively your alarm is not fully operational.
      I hope that this is helpful, you can always call us in the office on 01277 622932 between eight and five, weekdays, clients with contracts can have technical support 24/7.

  7. Mr Ray Colvin

    Hi There,
    I represent Bisley Village Hall which actually has 2 Halls, a main Hall of 155m2 and a smaller Hall of 69m2. We also have a couple of other rooms of 11m2.
    The Main Hall may have groups on average of about 30 persons which may include children or elderly persons. The Smaller Hall may have groups on average of about 12 persons.
    Over the whole week including weekends the main hall is occupied for 47hours on average and the smaller hall for 25hours. One of the smaller rooms is occupied for about 16hours per week.
    We currently have an L2 Fire Alarm System. Is there any need to upgrade to L1 at this time?

    1. Thank you for contacting us Ray, the answer to your question is that it depends and should be answered by your fire risk assessor as they would be taking liability for their recommendation.
      What we can say is that, an L1 design is a comprehensive level of automatic coverage, which includes any space bigger than 1 metre squared (large cupboards etc). L2 is also a risk assessed level of coverage and is in fact an L3 coverage with named additional areas. For example, under an L3 design, you cover the corridors and rooms opening onto corridors, but if you had a room within this room you would not cover this under an L3. If your risk assessor decided that this room should have automatic detection, for reasons that they would have specifically identified (perhaps a server room). Then this room would be specifically named on the fire alarm design certificate and for these reasons and L2 may only have one additional detector in addition to and an L3 design, or tens of additional detectors, depending upon the risk assessment. Our recommendation would be to consult your fire risk assessor and if you don’t have one or are looking for an alternative then please call us on 01277 622932.

  8. Hello Verity,
    I refer to your advice to Shyam on 22 Dec 2021 ref manual call points. I own a block of 3 flats about ten years old which have a comprehensive alarm system which links all three flats and includes a manual call point outside each flat. It is obviously very inconvenient to visit the flats every week and test each call point so can each point be replaced with an automatic sensor which would not require a weekly test.
    Many thanks

    1. Hello Tony,

      Technically anything can be done. However this is a fire risk assessment question. The only way to address a design issue such as this would be to involve a fire risk assessor. The fire risk assessor will advise you if you are permitted to make these changes based on their assessment of your current needs. You should be having regular fire risk assessments carried out and we recommend to have these done annually. If you have one then please contact them and book them in for a visit, but explain what you want to do and arrange to meet them on the day. If you need us to organise a fire risk assessment then please email and ask for Liam or call us directly on 01277 622932.
      Thank you – Paul

      PS Verity left WFP last year

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