Requirements for Fire Detection Systems in HMOs

What is an HMO?

HMOs are typically large houses that have been converted into flats or bedsits, such as student housing. ‘Houses in multiple occupation’ are defined by gov.uk as follows:

Your home is a house in multiple occupation (HMO) if both of the following apply:

  • at least 3 tenants live there, forming more than 1 household
  • you share toilet, bathroom or kitchen facilities with other tenants

It is important to note that the requirements for sheltered housing, such as supported living facilities, and self-catered rentals, such as holiday cottages are different, and not covered in this blog.

Kitchen facilities are often shared in HMOs
Shared kitchen spaces are a fire risk in HMOs

What grade of smoke alarm system is required for HMOs?

Within most HMOs, there are several acceptable options available for compliance with the Standard, depending on its size and configuration. 

The first option is to have Grade A fire alarm system installed throughout the building. This type of system consists of a conventional or addressable fire alarm panel, and then fire alarm detectors, call points, sounders and beacons are specified according to the layout and requirements of the property and manufactured to BS EN 54. It also requires a power supply to BS EN 54-4, and installation to BS 5839 Part 1.

However, in most cases, this level of coverage is not a requirement. In some small HMOs, for example, it may be acceptable to install a Grade D1 system. This is defined as a system incorporating one or more interlinked mains-powered smoke alarms (and heat alarms if required), each with an integral stand-by supply. They can be hardwire-interlinked or radio-interlinked, meaning that fire alarm panels are not required. The stand-by supply must be tamper-proof and last the full life of the alarm.

The final option, suitable for many medium and even large HMOs, is a mixed system. This involves the installation of Grade A components in communal areas, and any other high-risk areas identified by the risk assessment. Elsewhere in the premises, a separate Grade D1 system can be installed. This has become the preference, as it is likely to reduce the impact of nuisance alarms from individual flats on other occupants.

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Fire detection categories

The coverage within the building by the detection system is divided into three distinct categories. These are described with the following codes:

LD1 (highest level of coverage): Covers all circulation spaces that form part of escape routes plus all rooms in which a fire could start

LD2 (middle level of coverage): Covers all circulation spaces that form part of escape routes plus all rooms and areas that present a high fire risk to occupants

LD3 (lowest level of coverage): Covers circulation spaces that form part of the escape routes

Diagram showing levels of fire detection systems in HMOs

Any room which a building user must pass through, from another, in order to exit the premises would need detectors installed to satisfy these Categories. For example, if all rooms in a bungalow open onto a hallway which leads outside, only the hallway is considered a circulation space forming part of the escape route; if the only exit from the kitchen is into the dining room which then opens onto a hallway, the dining room would also need a detector under LD3 minimum protection as it is part of the escape route.

What category of fire detection is required within my HMO?

Different levels of coverage are needed in different areas of the building due to the risk of fire. This includes different Grades of fire detection system, as well as different configurations of components. For example, communal areas in HMOs are required to have Grade A systems, as they have particularly high levels of risk. This is due to the shared, and therefore often neglected responsibility for safety and housekeeping in HMOs. Moreover, the exact installation requirements within your HMO will depend upon the configuration and size of the premises. For more advice for landlords about fire safety in HMO’s, visit our help guide.

Messy kitchens are a health risk, and a fire hazard.
Responsibility for housekeeping can be neglected in HMOs. This is a fire risk,

Minimum levels of requirements for fire detection systems in HMOs:

The following is general guidance on the minimum levels of installation required in different scenarios.

One or two storey HMOs, where the area of each floor is less than 200sqm:

A Grade D1, category LD1 configuration should be installed in a new, or materially altered HMO. In an existing premises of this size, category LD2 is acceptable if it is already installed, but an LD3 system must be upgraded to comply with the Standard.

Areas within HMOs with more than 3 floors, or where the area of at least one floor is greater than 200sqm

Individual, one-room dwellings, with or without cooking facilities:

A Grade D1, category LD1 configuration should be installed. This is required in a new and existing HMO premises.

Individual dwellings comprising two or more rooms:

A Grade D1, category LD2 configuration should be installed. This is required in a new and existing HMO premises.

Communal areas

A Grade A, category LD2 configuration should be installed. This is required in a new and existing HMO premises.

Suitable Fire Detection Systems in HMOs

Always ensure that a comprehensive fire risk assessment has been carried out in your property by a competent person, to determine the risks specific to your premises. This is essential to protect the occupants, particularly as many tenants of HMOs are young and / or vulnerable renters. The Responsible Person for the building may be prosecuted if they cannot demonstrate that they have made every reasonable effort to comply with fire safety requirements enforced by their local council, particularly if a fire breaks out. Compliance with the Standards is the best way to ensure that this compliance can be achieved and evidenced.  

For additional guidance, please visit our Smoke Alarm Help and Information and BS 5839 summary page.

Frequently Asked Questions (FAQs)

What are the HMO fire alarm requirements?

HMO fire alarm requirements vary depending on the size and configuration of your property. For one or two-storey HMOs with floor areas less than 200sqm, you’ll need at minimum a Grade D1, category LD1 system for new or materially altered properties. This includes interlinked mains-powered smoke alarms with integral stand-by supplies. Existing properties of this size may maintain a category LD2 system if already installed, but any LD3 systems must be upgraded. For larger HMOs with more than 3 floors or floors exceeding 200sqm, communal areas require Grade A, category LD2 systems. Your specific HMO fire alarm requirements will be determined by a comprehensive fire risk assessment.

What are the HMO fire alarm testing requirements?

HMO fire alarm testing requirements state that all fire detection systems must be regularly checked to ensure proper functioning. As a landlord or property manager, you must ensure your HMO fire alarm testing requirements are met by conducting regular checks of all detection devices. Each alarm should be tested according to manufacturer guidelines, typically by pressing the test button to confirm the alarm sounds correctly. You must maintain a testing log that records dates, results and any issues identified. This documentation is crucial for demonstrating compliance with HMO fire alarm testing requirements during inspections by local authorities.

What are the HMO fire alarm system requirements?

HMO fire alarm system requirements specify that properties must have appropriate detection systems based on size and layout. For most HMOs, you have several options to meet the HMO fire alarm system requirements. You can install a Grade A system throughout (connected to a central panel), a Grade D1 system (interlinked mains-powered alarms with backup), or a mixed system with Grade A in communal/high-risk areas and Grade D1 elsewhere. Your HMO fire alarm system requirements will also include specific detection categories: LD1 (all circulation spaces and rooms), LD2 (circulation spaces and high-risk areas), or LD3 (circulation spaces only). The appropriate level depends on your property’s specific characteristics.

What are the three storey HMO fire alarm requirements?

Three storey HMO fire alarm requirements typically necessitate a more comprehensive detection system due to increased evacuation challenges. If your three storey HMO has floor areas exceeding 200sqm, communal areas must have a Grade A, category LD2 system with a central control panel. Individual dwellings within your three storey HMO should have Grade D1 systems – category LD1 for single-room dwellings and category LD2 for multi-room dwellings. These three storey HMO fire alarm requirements aim to provide early warning throughout the property, particularly in escape routes and high-risk areas like kitchens, where fires commonly start in shared accommodations.

What are the HMO fire detection requirements?

HMO fire detection requirements specify the type, grade and category of detection systems needed in your property. Your HMO fire detection requirements will vary based on your property’s size and configuration. For smaller HMOs (one or two storeys under 200sqm), a Grade D1 system with LD1 or LD2 coverage is typically required. For larger properties, communal areas need Grade A systems with LD2 coverage. The HMO fire detection requirements also specify that all escape routes must be covered by appropriate detection devices. Different types of detectors (smoke, heat or combined) may be needed in different areas based on the specific fire risks identified during your assessment.

What are the HMO smoke alarm requirements?

HMO smoke alarm requirements mandate that appropriate detection devices be installed throughout your property. Your HMO smoke alarm requirements will include using interlinked alarms, ensuring that when one detector is triggered, all alarms sound throughout the property. For most HMOs, mains-powered smoke alarms with battery backup (Grade D1) are required in escape routes and risk areas. The HMO smoke alarm requirements also specify that different detector types should be used in different locations – for example, heat detectors rather than smoke alarms in kitchens to reduce false alarms. All devices must comply with relevant standards, including BS EN 54 for manufactured components and BS 5839 Part 1 for installation.

What are the 2 storey HMO fire alarm requirements?

Two storey HMO fire alarm requirements typically specify a Grade D1, category LD1 system for new or altered properties. This means your 2 storey HMO fire alarm requirements include installing interlinked, mains-powered smoke alarms with integral stand-by power supplies throughout circulation spaces and all rooms where a fire could start. For existing 2-storey HMOs with floor areas less than 200sqm, a category LD2 system may be acceptable if already installed. Your 2 storey HMO fire alarm requirements aim to ensure all occupants receive early warning of fire, particularly important in shared accommodations where responsibility for fire safety can be fragmented.

What is the HMO fire alarm system cost?

HMO fire alarm system cost varies depending on the size of your property and the grade of system required. For a smaller HMO requiring a Grade D1 system, your HMO fire alarm system cost might start from approximately £300-£600 for the basic components, including interlinked mains-powered smoke alarms with battery backup. For larger properties requiring Grade A systems with control panels, your HMO fire alarm system cost could range from £1,000 to several thousand pounds. Additional factors affecting your HMO fire alarm system cost include installation, which should be carried out by qualified professionals, and ongoing maintenance expenses. While this represents a significant investment, it’s essential for legal compliance and tenant safety.

What is the HMO fire alarm testing frequency?

Your HMO fire alarm testing frequency should include weekly tests of the system by pressing the test button on at least one detector (on a rotational basis). Monthly checks should examine the control panel (if installed) for fault indicators. Your HMO fire alarm testing frequency should also include bi-annual professional servicing by qualified technicians, who will conduct more thorough examinations of all components. This HMO fire alarm testing frequency ensures continuous protection for tenants and helps identify issues before they compromise safety.

Are HMO smoke alarms in bedrooms required?

HMO smoke alarms in bedrooms are typically required as part of a comprehensive fire detection system. You should install smoke alarms in HMO bedrooms because these areas contain potential fire hazards, such as electrical equipment and are occupied during sleeping hours when occupants are most vulnerable. The HMO smoke alarms in bedrooms should be interlinked with all other alarms in the property, ensuring that a fire detected in any location will trigger all alarms. For grade D1 systems, these HMO smoke alarms in bedrooms should be mains-powered with battery backup. This requirement is particularly important in buildings with multiple occupants who may be unfamiliar with escape routes.

What is a Grade A fire alarm system in an HMO, and when is it required?

A Grade A fire alarm system in an HMO is a comprehensive detection setup that includes a central control panel connected to various detection devices throughout the property. You would need a Grade A fire alarm system in an HMO with more than three floors or where any floor exceeds 200sqm in area. A Grade A fire alarm system in an HMO must be installed in communal areas of these larger properties, providing category LD2 coverage (all circulation spaces and high-risk areas). The system components must be manufactured to BS EN 54 standards, with installation following BS 5839 Part 1 guidelines. A Grade A fire alarm system in an HMO offers enhanced monitoring capabilities and reliability for larger shared accommodations.

Do I need a fire alarm in an HMO?

Yes, you absolutely need a fire alarm in an HMO – it’s a legal requirement for all houses of multiple occupation. The specific type of fire alarm in an HMO that you need depends on your property’s size and configuration. At a minimum, you’ll need interlinked smoke detectors covering escape routes, with additional detectors in high-risk areas and potentially in all rooms for larger properties. Failure to install an appropriate fire alarm in an HMO can result in significant penalties, including fines and prohibition notices that prevent you from renting your property.

Is a fire risk assessment a legal requirement for HMOs?

Yes, a fire risk assessment is a legal requirement for HMO properties under the Regulatory Reform (Fire Safety) Order 2005. You must ensure that a fire risk assessment is completed for HMO compliance as it is a legal requirement. This assessment should be conducted by a competent person who can identify specific hazards in your property. The fire risk assessment is a legal requirement for HMO owners to protect tenants and demonstrate due diligence to authorities. It must be reviewed regularly and updated whenever significant changes occur to the property or occupancy. The assessment should identify potential fire hazards, evaluate who might be at risk, and determine what fire safety measures are needed to achieve compliance.

Managing False Alarms

Managing false alarms is a public safety issue. As reported by the BBC, in 2020 the Chief Fire Officer (CFO) at Lincolnshire Fire and Rescue – Les Britzman – asked business owners to take more care and responsibility in managing false alarms. Provided that there are no hazardous materials in the premises and there is no immediate risk to life or the community, the CFO stated that organisations should “have systems in place to go and check those buildings themselves” before calling 999 if a fire is discovered.

Despite this, a National Statistics report shows that FRSs in the UK attended 246,529 fire false alarms in 2023. This was a 3.1% increase on the previous year, and a 6.3% increase on figures 5 years ago. Last year (2023) saw the largest number of false alarms attended since 2011. This diverts essential resources from real emergencies and puts people at risk due to avoidable blue light journeys.

Islington Fire Station, London.
Islington Fire Station, London. The station is part of the London Fire Brigade network of emergency responders.

Further to wasting public resources, management and mitigation of false alarms ensures that time is not wasted by needless evacuations. Unnecessary evacuations may cause downtime of machinery, and potentially a loss of earnings. If false alarms are allowed to persist, occupants may become desensitized to the sound. This puts lives at risk, as in a real emergency occupants may fail to react properly.

The importance of managing false alarms

BS 5839 Part 1, the Code of Practice for design, installation, commissioning and maintenance of fire alarm systems in non-domestic premises, has a focus on managing false alarms. Therefore, managing fire alarms is recommended for organisations to demonstrate that they are acting responsibly to prevent fires.  To achieve this, the Responsible Person must ensure that all false alarms on a system are logged. Each false alarm must also be investigated for a root cause, which must be addressed. Mitigating work must be undertaken as necessary to prevent the same incident occurring again. To learn more about this Standard, see our summary of BS 5839-1: 2017.

Should a real fire occur, documentation including a record of, and mitigation work following past false alarms will be required during the investigation. The maintenance of these records is not a legal requirement. However, correct documentation can prevent prosecutions of negligence. It is also highly likely that insurers will require these records when processing a claim.

How to prevent false alarms

Preventing false alarms can be as simple as fitting flip covers to manual call points to prevent accidental activations. Indeed, this is now a recommendation in the Standard, though not a requirement. However, if a false alarm occurred because a manual call point was accidently triggered, the need to mitigate against repeat occurrences may necessitate their installation.

Fire Alarm System Testing & Maintenance
Functional testing of point smoke detectors with a Solo aerosol dispenser and access pole.

Another fundamental part of managing false alarms in existing fire alarm systems is to ensure they are maintained. This includes regular testing, inspections, and servicing. This will reduce the risks of false alarms caused by faulty or improperly installed equipment, as well as ensuring that the system is effective in an emergency.

Premises with a change of use should be professionally inspected to identify whether the existing fire alarm system remains suitable. For example, replacing optical beam detectors with a system of point heat detectors would prevent false alarms in a storage warehouse that has been converted into a factory with machinery that creates a lot of dust.

Optimising new fire alarm systems

For new fire alarm systems, during the design stage the full details of the Fire Risk Assessment, the building, and its intended / current use should be made available. This ensures that the most suitable types of detector can be selected, and positioned in the correct way. Suitable detectors in the correct locations are one of the easiest methods for managing false alarms. For example, installing an optical smoke detector near kitchens or bathrooms could result in false alarms due to steam from cooking or baths and showers.

Identifying design shortcomings is not generally the responsibility of an installer. However, the Standard does state that any issues noticed during installation – particularly those arising from features of the building that might not have been known to the designer – should be brought to the attention of the designer or Responsible Person.

Fire Risk Assessments must be kept up to date and carried out by a competent person.
Fire alarm systems should be tailored to the building. It should account for the risks identified in the building’s fire risk assessment.

False alarms put unnecessary strain on UK fire services, diverting essential resources away from real fires, and putting lives at risk. Managing false alarms is in the interest of organisations as it prevents disruption.

Safelincs provide nationwide fire alarm system servicing and maintenance contracts at competitive pricing. View our Servicing and Maintenance page or call our Servicing team on 0800 612 4827 for more information.

Daniel Bennett

Compliance and Data Analyst

Daniel is our Senior Product Manager. He has a wealth of knowledge when it comes to emergency lighting, fire alarms, smart products, and fire extinguishers.

Latest Posts by Daniel Bennett

Managing False Alarms19th March 2024