Why every home should consider interconnected (interlinked) smoke alarms

This guide explains what interlinked smoke alarms are, the benefits of interlinked smoke alarms at home, UK regulations, installation options, and how to keep your system in top condition.

What are interconnected smoke alarms?

An interconnected (or interlinked) smoke alarm system links multiple detectors together — either via hardwiring or wireless radio signals — so they all trigger simultaneously in the event of smoke or fire detection.

Types of interconnection:

• Hardwired systems: Physical cables connect alarms, usually installed in new builds or major renovations.
• Wireless systems: Radio-frequency or smart-enabled alarms link without cables, ideal for retrofitting existing homes.

Many modern systems can also integrate heat alarms for kitchens and carbon monoxide (CO) alarms, creating a fully networked home safety solution.
Learn more about mains-powered smoke alarm installation

Why they matter: key benefits

The benefits of interlinked smoke alarms at home go far beyond standard, standalone alarms:

1. Whole-home coverage
   • If smoke is detected in one room, every connected alarm sounds, alerting you wherever you are in the house — even behind closed doors or in a loft conversion.
2. Early warning for sleeping occupants
   • Particularly important for multi-storey properties, where a fire downstairs might otherwise go unnoticed until it’s too late.
3. Enhanced safety for vulnerable residents
   • Elderly people, children, or those with reduced mobility benefit from maximum reaction time.
4. Improved compliance with UK regulations
   • Interlinked alarms are now a legal requirement in certain UK homes, especially new builds and rental properties.
5. Future-proof technology
   • Wireless systems allow easy expansion and integration with smart home apps for real-time alerts.
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Regulatory requirements & standards

UK requirements vary by nation but are guided by BS 5839-6, which sets standards for domestic fire alarm systems.

• England & Wales: New multi-storey homes and Houses in Multiple Occupation (HMOs) require interlinked alarms.
• Scotland: Since February 2022, all homes must have interlinked smoke and heat alarms.
• Northern Ireland: Interlinked systems required for new builds and HMOs.

BS 5839-6 categories:

• Grade D1: Mains-powered alarms with tamper-proof backup batteries.
• Grade D2: Mains-powered alarms with user-replaceable batteries.

Interlinked alarms are considered a best practice enhancement under the standard.

Installation & placement guidelines

• Placement:
  • Smoke alarms: Hallways, landings, living rooms, bedrooms.
  • Heat alarms: Kitchens, garages, loft spaces.
• Height: Mount on ceilings, at least 300 mm from walls.
• Interlinking: Follow manufacturer pairing or wiring instructions to ensure all units communicate.

Maintenance & lifespan

To keep your interlinked system reliable:

• Test monthly: Use the test button to check all alarms sound together.
• Clean biannually: Lightly vacuum to remove dust and insects.
• Replace units: Smoke alarms every 10 years; heat alarms per manufacturer guidance.
• Check batteries: Even in mains-powered units, backup batteries must be operational.

Read our testing and maintenance tips

The benefits of interlinked smoke alarms at home are clear: faster alerts, wider coverage, and increased safety for all occupants. Whether you choose hardwired or wireless, installing an interconnected system is one of the most effective steps you can take to protect your household.

For more advice on choosing and installing the right system for your property, explore our