Fire Alarms for HMOs: Cost and the Right Specification
By the DC Fire & Security engineering team — installing and maintaining fire and security systems since 2010. Updated June 2026.
Quick answer
Small shared-house HMOs (up to two storeys, sound escape routes) typically need a Grade D1 system: interlinked mains smoke alarms on escape routes and living rooms plus kitchen heat — £400–£900 installed. Larger or higher-risk HMOs (3+ storeys, bedsits) step up to Grade A panel systems to BS 5839-1 with call points and sounders — £1,500–£4,000+. Your council's licensing schedule is the binding spec.
The two specification worlds
| Grade D1 (domestic-style) | Grade A (panel system) | |
|---|---|---|
| What it is | Mains interlinked alarms with battery backup | Full BS 5839-1 system: panel, call points, detectors, sounders |
| Typical HMO | 1-2 storey shared houses, good escape routes | 3+ storeys, bedsits, complex layouts, higher risk |
| Coverage | LD2 standard: escape routes + living rooms + kitchen heat | Per design: commonly escape routes + rooms + heat in lettings/kitchens |
| Installed cost | £400–£900 typical | £1,500–£4,000+ by size |
| Testing | Monthly button tests, logged | Weekly call point tests + 6-monthly servicing |
| Who decides | Council licensing schedule / LACORS | Same — plus BS 5839 design |
Reading your council's schedule (and LACORS)
HMO fire detection isn't a free design space: the LACORS housing fire safety guidance provides the national framework and your licensing authority's schedule applies it — storey count, layout, escape route quality and cooking arrangements drive the banding. The recurring specifics: heat (never smoke) in kitchens; detection in lettings where bedsit-style cooking or higher risk exists; interlink so the house wakes together; emergency lighting joining the spec on larger HMOs; and in converted buildings with poor compartmentation, the mixed-system logic our communal alarms guide explains. Pre-licensing inspections fail installs that freelanced around the schedule — we install to the named council's current requirements and say so on the certificate, which is what their officers want to see.
Costs, upgrade paths and landlord practicalities
Realistic installed money: 4-bed shared house Grade D1 LD2 (5–7 devices, interlinked mains or sealed radio-link): £400–£900; 6-bed three-storey with Grade A spec (compact panel, call points, sounders, escape + letting coverage): £1,500–£3,000; larger/bedsit HMOs beyond. Wireless interlink (radio-linked Grade D, EN 54-25 Grade A devices) saves redecoration in occupied lets at the usual 20–40% device premium — usually net-cheaper after making-good is priced. Ongoing: monthly logged tests (Grade D) or weekly + 6-monthly servicing (Grade A — £200–£400/yr), records your licence renewal will request. Portfolio landlords: we standardise specs across stock and fold testing/servicing into one annual round with the smoke/CO compliance checks — one file per property, renewals without panic.
Frequently Asked Questions
Can I just fit battery smoke alarms in my HMO?
Do I need detection inside every bedroom?
Who does the weekly/monthly tests — me or tenants?
What happens if my HMO alarm doesn't match the licence?
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