Do You Need an Addressable Fire Alarm for a Block of Flats or HMO

Fire alarm requirements in residential buildings can be confusing, especially when it comes to deciding whether a conventional system is enough or whether an addressable system is required.
Across the buildings we assess in Chester, the North West and North Wales, this is one of the most common questions responsible persons ask.

This page explains the difference, the legal expectations and when an addressable system becomes the correct and safest choice.

Start with the building type

Different residential settings have different expectations for fire alarm systems.

Blocks of flats

Most purpose built flat blocks follow a stay put strategy and rely on domestic smoke alarms inside flats and detection in common areas.
Addressable systems may be recommended when the building:

  • Has complex layouts

  • Has a history of false alarms

  • Contains vulnerable occupants

  • Includes basement levels or extended corridors

  • Has fire doors or compartmentation concerns

HMOs and conversions

HMOs have higher fire risk because they involve:

  • Multiple, unrelated occupants

  • Higher fire load

  • Poorer fire door condition

  • Mixed sleeping patterns

  • Varying levels of occupant awareness

Addressable systems are far more suitable in these environments, especially in larger or multi storey HMOs.

Serviced accommodation

Short term stays mean people are less familiar with escape routes.
Addressable detection offers better performance, clearer information and faster investigation.

When an addressable system is strongly recommended

1. The building has multiple floors or long corridors

Addressable alarms allow you to pinpoint the exact detector.
In multi storey residential buildings, this saves time and reduces confusion during evacuations or investigations.

2. You have repeated false alarms

False alarms in residential settings can cause:

  • Tenant disruption

  • Evacuations at night

  • Loss of confidence in the alarm

  • Fire service callouts

  • Enforcement attention

Addressable systems reduce false alarms using programmable sensitivity and better diagnostics.

3. You need fast identification of faults

In HMOs and mixed residential blocks, faults can go unnoticed or unreported.
Addressable systems identify:

  • Detector failures

  • Cable faults

  • Loop issues

  • Dirty or compromised call points

This helps responsible persons maintain compliance.

4. The fire risk assessment identifies shortcomings

FRA recommendations often trigger upgrades because the original system no longer matches the building’s risk profile.

Common issues include:

  • Inadequate coverage

  • Wrong category of system

  • Faulty detection in escape routes

  • Changes in occupancy

  • Introduction of sleeping risk

  • Altered layouts

If your FRA says an upgrade is needed, it carries legal weight.

5. You manage vulnerable or high risk residents

Addressable detection improves clarity, speed and control in buildings that house:

  • Students

  • Elderly residents

  • Night workers

  • Families

  • Tourists

  • People with additional support needs

The more complex the occupancy, the more valuable addressable detection becomes.

6. The current system is obsolete

Older conventional systems eventually become unreliable or unsupportable.
When parts are unavailable, the only realistic solution is to install a modern system.

When a conventional system may still be acceptable

A conventional system may be suitable if your building is:

  • Small

  • Simple in layout

  • Low risk

  • Consistent in occupancy

  • Well compartmentalised

  • Equipped with functional domestic alarms in flats

  • Well maintained

Even then, many managing agents now prefer addressable systems because they improve long term reliability and reduce callout costs.

What the fire services are looking for

Across the region, inspectors increasingly expect:

  • Clear call point identification

  • Reliable fault reporting

  • Consistent sound levels

  • Minimal false alarms

  • Proper coverage in escape routes

  • Evidence of maintenance

Addressable systems make these easier to achieve.

The Fletcher Risk approach

We provide independent advice on fire alarm suitability for:

  • HMOs

  • Converted flats

  • Purpose built blocks

  • Heritage residential buildings

  • Mixed use residential and commercial properties

Our assessments include:

  • Full alarm system review

  • Category check (Grade A, D etc)

  • Coverage evaluation

  • Sound testing

  • Equipment condition

  • FRA linked recommendations

We are not tied to any installation company, so our guidance is unbiased.

Book a fire alarm system review or speak to the team:
https://www.fletcherrisk.co.uk

Disclaimer

This page provides general guidance only. It does not constitute legal advice and should not be relied upon as a substitute for a full fire risk assessment or professional consultation. Fire safety requirements vary depending on building type, condition and occupancy. Fletcher Risk Management Ltd accepts no liability for decisions made based on this content. Always consult a competent professional for guidance on your specific property.

Fletcher Risk Team - 25 November 2025

Tim Fletcher