Fire Alarms for HMOs: What Grade and Category You Need, and What It Costs

What grade and category of fire alarm does an HMO need?

Table C4 of the LACORS guide is the benchmark most councils use: Grade D for shared houses of up to four storeys, Grade A for five or six storeys, and a mixed system for bedsits. These are for normal-risk houses, so a higher-risk house can be asked for more.

LACORS (July 2008) is the national guidance councils use to judge fire safety in existing HMOs under the Housing Act 2004. It is a benchmark, not a law, and each council can set its own licensing standard on top. Check yours before you buy anything.

A shared house is let to a group who share the kitchen and living room. A bedsit HMO has separate lettings, often with cooking in each room. The difference matters more than the number of tenants.

What do Grade A, Grade D, LD2 and LD3 mean?

The grade is how the system is built: Grade A is a control panel with detectors and call points, Grade D is mains-powered alarms with a built-in backup battery. The category is where the detectors go: LD3 covers the escape route only, LD2 adds the risk rooms, LD1 covers nearly every room.

Both come from BS 5839-6, the British Standard for fire alarms in homes. LACORS was written against the 2004 edition. The current 2019 edition dropped Grades B and E and split Grade D into D1 and D2. LACORS says battery-only alarms (Grade F) are not recommended in HMOs, and in grades D and F every alarm must be interlinked so they all sound together.

Many councils now ask for Grade D1 rather than D2 in new HMO installations, because a sealed battery cannot be taken out by a tenant. Check your council's standard.

• LD3: detectors in the escape route only, the hall, stairs and landings
• LD2: LD3 plus every room with a high fire risk, such as the kitchen and lounge
• LD1: detectors in the escape route and every room where a fire could start, except bathrooms and toilets

Why does an HMO kitchen need a heat detector, not a smoke alarm?

Because cooking sets off smoke alarms, and constant false alarms make tenants disconnect them. LACORS puts an interlinked heat alarm in the kitchen and smoke alarms on the escape route and in the lounge.

For a shared house of three or four storeys, the LACORS case study lists interlinked mains smoke alarms with battery backup on the escape route at every floor, an interlinked heat alarm in the kitchen, an interlinked smoke alarm in the lounge, and interlinked smoke alarms in any cellar.

In bedsits with their own cooking, LACORS uses an interlinked heat alarm in each room, so a fire there warns the whole house, and a separate smoke alarm that is not interlinked, so one tenant's burnt toast does not wake everyone else.

The alarm system works alongside the fire doors and the protected escape route. See our guide to HMO fire doors.

Who tests an HMO fire alarm, and how often?

For a Grade D system, LACORS says the alarms should be tested every month with the test button, by the landlord or by tenants who have been shown how. For a Grade A panel, one detector or call point per zone should be tested weekly and a competent engineer should service it every six months.

The Management of HMOs (England) Regulations 2006 require the manager to keep fire alarms in good working order. LACORS also recommends that every detector in any system is checked at least once a year to confirm it responds to smoke, recorded in a log book with a certificate.

Some licence conditions ask for more than this, such as weekly checks or a named person to test. Your licence wins over the guidance, so read it.

What fire alarm will the council expect when I license an HMO?

At minimum, the alarm in their own HMO standard, which is usually based on LACORS, plus a smoke alarm on every storey and a carbon monoxide alarm in any room with a fixed combustion appliance. Licensed HMOs must meet those 2022 smoke and CO rules through their licence conditions.

Mandatory licensing covers HMOs with 5 or more people forming 2 or more households. Many councils also run additional licensing for smaller HMOs. The Housing Act 2004 requires every HMO licence to include conditions on smoke and carbon monoxide alarms, and the landlord must give the council a declaration about their condition and position when asked.

Councils commonly ask for the installation certificate and the latest test or service record with the application. The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 added the carbon monoxide duty from 1 October 2022: a CO alarm in any room used as living accommodation with a fixed combustion appliance, such as a boiler or wood burner, but not a gas cooker.

The Fire Safety Order 2005 also applies to the shared parts of an HMO, so you need a fire risk assessment for them. Our HMO fire safety guide for landlords covers the full picture.

How much does an HMO fire alarm cost?

A small Grade A panel system starts from around £4,000 installed. A Grade D mains-wired system for a two to four storey shared house costs much less, and we price it from photos and a floor-by-floor list of rooms.

Cost depends less on the number of tenants and more on how the cables get to each alarm without damage to decoration, and on whether any existing wiring can be reused.

How can DC Fire & Security help with an HMO fire alarm?

We design, install and service fire alarm systems for HMOs and other buildings across Bedfordshire, Hertfordshire, Buckinghamshire and London.

Send us photos, the number of floors and rooms, and your council's HMO standard, and we will tell you which grade and category the house needs before you spend anything. We also inspect and repair the fire doors the alarm works with.

Sources

• LACORS: Housing - Fire Safety, guidance on fire safety provisions for certain types of existing housing (July 2008, council copy), Table C4 and paragraph 32.5
• BSI Knowledge: BS 5839-6:2019, fire detection and fire alarm systems in domestic premises (current as BS 5839-6:2019+A1:2020)
• Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022
• GOV.UK: Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022, guidance for landlords and tenants
• Housing Act 2004, Schedule 4 (licence conditions)
• Management of Houses in Multiple Occupation (England) Regulations 2006
• Licensing of Houses in Multiple Occupation (Prescribed Description) (England) Order 2018
• Regulatory Reform (Fire Safety) Order 2005

Updated October 2026 by Sebastian Grabowski, DC Fire & Security. We design, install and service fire alarm systems across Bedfordshire, Hertfordshire, Buckinghamshire and London.