BS 5839‑6: A Complete Guide to Domestic Fire Alarm Standards
What is BS 5839-6?
BS 5839‑6 is the British Standard for fire detection and fire alarm systems in domestic premises. It provides clear recommendations for designing, installing, and maintaining fire alarms in:
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Houses and bungalows
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Flats and maisonettes
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Houses in Multiple Occupation (HMOs)
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Supported and sheltered housing
Following this standard ensures early warning of fire, reduces false alarms, and helps meet legal fire safety obligations.
Who Should Follow BS 5839‑6?
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Landlords & HMO Owners – BS 5839‑6 is the recognised benchmark for HMO licensing and landlord fire safety compliance.
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Homeowners – Not a legal requirement but recommended for enhanced life protection, especially in multi-storey homes.
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Housing Associations & Care Providers – Essential for supported housing and vulnerable residents.
Grades of Fire Alarm Systems Explained
BS 5839‑6 uses Grades to define the type of alarm system required:
BS 5839-6 Fire Alarm System Grades
| Grade | Power Source | Battery Type | Interlinked? | Where It’s Used |
|---|---|---|---|---|
| Grade A | Mains-powered | Control panel backup | Yes (via control panel) | Large HMOs, care homes, high-risk buildings |
| Grade C | Mains-powered | Backup supply | Yes (hardwired or RF) | Larger homes, higher-risk rental properties |
| Grade D1 | Mains-powered | Sealed long-life battery | Yes (hardwired or RF) | Standard for modern homes & HMOs |
| Grade D2 | Mains-powered | Replaceable battery | Yes (hardwired or RF) | Budget rentals, older systems |
| Grade F1 | Battery only | Sealed long-life battery | Optional | Owner-occupied, low-risk homes |
| Grade F2 | Battery only | Replaceable battery | Optional | Not recommended for rental use |
Fire Protection Categories (LD1, LD2 & LD3)
| Category | Where Alarms Are Installed | Protection Level | Typical Use |
|---|---|---|---|
| LD1 | All rooms, escape routes, hallways, landings | Maximum | Large HMOs, high-risk homes |
| LD2 | Escape routes & high-risk rooms (kitchen, lounge) | Medium | Most HMOs & rental properties |
| LD3 | Escape routes only (hallways & landings) | Basic | Low-risk, owner-occupied homes |
Key Changes in BS 5839‑6:2019+A1:2020
✔ Split Grades (D1/D2, F1/F2) – Long-life, tamper-proof batteries now strongly recommended.
✔ Multi-Sensor & Optical Alarms Preferred – Reduces nuisance alarms compared to ionisation detectors.
✔ Interlinking Alarms – All alarms should activate together for maximum safety.
✔ Additional Guidance for Supported Housing – Special considerations for vulnerable residents.
If your fire alarm system is over five years old, it may no longer meet these recommendations.
Why Following BS 5839‑6 is Important
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Life Safety – Early detection gives occupants vital time to escape.
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Legal Compliance – Essential for landlords & HMO owners under fire safety legislation.
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Insurance Protection – Non-compliant systems may invalidate insurance policies.
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Reassurance for Residents – Demonstrates your commitment to safety.
Need Help Meeting BS 5839‑6?
If you’re unsure whether your property meets current standards, we can help.
At Cobra Fire & Security, we provide:
✔ BS 5839‑6 Compliant Fire Alarm Installation
✔ Upgrades to Meet 2019+A1 Recommendations
✔ Maintenance & Servicing for Landlords & Homeowners
📞 Contact us today for expert advice and a free consultation.
Reviewed: 20/07/2025 Our articles are reviewed regularly. However, any changes made to standards or legislation following the review date will not have been considered. Please note that we provide abridged, easy-to-understand guidance. To make detailed decisions about your fire safety provisions, you might require further advice or need to consult the full standards and legislation.
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Written by : Michael Winter
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