Short answer. Most houses in multiple occupation (HMOs) need a fire alarm designed to BS 5839-6. The fire risk assessment, licence conditions and LACORS guidance set the grade and category. The common parts of larger HMOs and blocks of flats fall under the Fire Safety Order, and a communal system there is normally designed to BS 5839-1. Hawthorne designs, installs, services and monitors these systems for landlords and managing agents across Norfolk, Suffolk and Cambridgeshire, often using wireless equipment so occupied homes need no rewiring.
The rules that apply to rented and shared housing
Housing Act 2004. Councils inspect rented homes using the Housing Health and Safety Rating System (HHSRS), and fire is one of the hazards it scores. In England, an HMO with five or more occupiers forming two or more households needs a mandatory licence. Councils can also run additional licensing schemes that bring smaller HMOs into licensing. Licences normally carry fire alarm conditions, so we design to the licence schedule.
LACORS guidance. Housing – Fire Safety (LACORS, 2008) is still the guidance most council housing teams apply to existing HMOs, bedsits and converted blocks. It gives worked examples by property type and storey count. Smaller shared houses often end up with mains-powered, interlinked alarms. Larger bedsit-type HMOs over three or more storeys are often specified with a control panel.
BS 5839-6 grades and categories
BS 5839-6:2019+A1:2020 covers dwellings and HMOs. Grade is how the system is built; category is where detection goes.
| Grade or category | What it means |
|---|---|
| Grade A | Separate detectors, sounders and call points with a control panel and standby power, using BS EN 54 equipment |
| Grade C | Detectors and sounders (which may be combined as alarms) on a common mains supply with standby power and central control equipment |
| Grade D1 / D2 | Mains-powered smoke and heat alarms, each with a standby battery, tamper-proof in D1 and user-replaceable in D2, interlinked by cable or radio |
| Grade F1 / F2 | Battery-only alarms, not normally the main system in an HMO |
| LD1 | Escape routes and every room where a fire could start, except bathrooms and toilets |
| LD2 | Escape routes plus specified higher-risk rooms, such as kitchens and living rooms |
| LD3 | Escape routes only |
When BS 5839-1 applies. A communal system in the common parts of a larger HMO or block of flats is designed to BS 5839-1, the non-domestic standard. Purpose-built blocks with a stay-put strategy do not normally have a communal alarm at all. Detection in their common parts is often there to open the smoke vents (AOVs). The fire risk assessment should say which applies. See our BS 5839 compliance guide.
Fire Safety Order and the 2022 Regulations. The Regulatory Reform (Fire Safety) Order 2005 applies to the common parts of HMOs and blocks of flats. Since the Fire Safety Act 2021 it also covers the structure, external walls and flat entrance doors. The responsible person, usually the freeholder, landlord or managing agent, must keep a suitable fire risk assessment. The Fire Safety (England) Regulations 2022, in force since 23 January 2023, add resident fire safety information in all such buildings, quarterly communal fire door checks and annual flat entrance door checks over 11 metres, and further duties at 18 metres or seven storeys. Our article on 2026 fire safety changes covers evacuation plans for taller blocks.
Smoke and carbon monoxide alarms. Since 1 October 2022, the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 have required landlords in England to fit a smoke alarm on every storey with living accommodation. They must also fit a carbon monoxide alarm in any room with a fixed combustion appliance other than a gas cooker. That is the minimum. In an HMO, the licence and fire risk assessment usually require a full BS 5839-6 system, interlinked so that a fire detected anywhere sounds the alarm everywhere.
Why wireless suits tenanted buildings
- No rewiring through people's homes. Devices link by radio, so there are no new cable runs through bedrooms and far less making good.
- Less time on site. Fewer days of disruption. On one recent project, wireless came in over £2,000 below wired for the same building.
- The right standards. In a Grade A system the radio devices should be certified to BS EN 54-25, the standard for radio-linked fire components. Mains-powered alarms in a Grade D system can be radio-interlinked under BS 5839-6.
- Batteries to manage. Wireless devices run on batteries that last years, not forever. We check and replace them at service visits, and the system flags low batteries.
Our recent shared-housing systems have been wireless or radio-interlinked. In an empty building with easy cable routes, wired can still be cheaper, so we price both. See commercial fire alarm systems.
Testing, servicing and the log book
BS 5839 recommends that panel systems are tested weekly from a different call point each time. A competent engineer should also service them at least every six months. Grade D alarms should be tested regularly, usually monthly. Record every test, fault and visit in a log book kept on site. Assessors ask for it, and it is often missing. See how often to test and service a fire alarm and fire alarm certificates.
If nobody suitable is on site, we can do the weekly test. In blocks the same visit can cover the dry risers, AOVs, lift emergency call button and a walk-round of fire doors and lights.
What we have done for landlords and managing agents
We work for private landlords, managing agents and block management companies across Norfolk and Cambridgeshire, from new wireless systems to long-term maintenance of occupied blocks. Recent examples:
- Shared houses, Norwich. We installed a Grade A, Category LD2 wireless system to BS 5839-6 across two adjoining shared houses, with smoke detection in bedrooms and communal areas, heat detection in kitchens and call points at exits. Being wireless, it needed no cable runs between devices.
- Apartment blocks, Norwich. For managing agents we carry out weekly testing and monitored fire alarm maintenance, alongside emergency lighting, fire doors, dry risers and smoke vents. When we take over from another provider we bring the records and equipment back to standard: on one recent takeover the first visit found no log book, no record of weekly testing and life-expired standby batteries.
- Residential blocks, Cambridge. We maintain the fire alarm systems across several residential blocks for a block management company.
What it costs
These figures are from Hawthorne's own invoices and exclude VAT.
- A new system for a block of three flats: £2,500 to £3,000
- A wireless Grade A system across two shared houses: about £6,400
- Annual maintenance for a managed residential block: £168 to £288
- Annual maintenance for larger residential or mixed-use blocks: £545 to £1,442
More detail: installation costs, servicing costs and the pricing calculator.
How we work with landlords and agents
Landlords and agents get one contact across a portfolio, quotes itemised against the licence or fire risk assessment, certificates and log books at handover, and visits booked around tenants. Maintenance-contract customers get a 4-hour response to emergencies and same-day response to non-emergency faults. We also handle door entry, access control and communal CCTV for blocks.
We hold SSAIB certification (NORF034) for fire, intruder, CCTV and access control, plus ISO 9001, ISO 14001 and Cyber Essentials. We are an Ajax approved installer, a Paxton Gold Partner and a Hikvision Platinum Partner.
If you manage a taller block, the free residential high-rise fire safety checklist is available on our commercial fire alarms page.
Frequently asked questions
What fire alarm does an HMO need?
Usually a BS 5839-6 system. Smaller shared houses often have a Grade D system of mains-powered, interlinked alarms. Larger HMOs and bedsit-type properties are often Grade A with a control panel. The category, usually LD2 or LD3, sets where detection goes, and the licence conditions and fire risk assessment set the final specification.
Is a wireless fire alarm acceptable in an HMO?
Yes, if designed to the right standard. BS 5839-6 allows radio-interlinked alarms, and Grade A radio devices should be certified to BS EN 54-25.
Who is responsible for testing the fire alarm?
The landlord, licence holder or managing agent, as the responsible person. Panel systems should be tested weekly and serviced at least every six months, with everything recorded in a log book. We can do the weekly test if nobody suitable is on site.
Does a block of flats need a communal fire alarm?
Not always. Purpose-built blocks with a stay-put strategy do not normally have one, though detection may open the smoke vents. Converted blocks and larger HMOs often do need one, designed to BS 5839-1. The building's fire risk assessment should say which applies.
Do landlords have to fit carbon monoxide alarms?
In England, yes, since October 2022: in any room with a fixed combustion appliance other than a gas cooker. Alarms must work at the start of each tenancy and be repaired once a fault is reported.
Can you take over servicing from another company?
Usually, yes. The first visit takes longer because the log book, zone chart or panel codes are often missing. We put the paperwork right and quote any remedial work separately. Managing agents can bring several buildings under one contract.
Get a quote
Contact the team for a free survey. Send the HMO licence schedule or fire risk assessment if you have them, and we will design to it.
Last updated: October 2026