Install emergency lighting.

Emergency lighting — the lights that come on automatically when mains power fails — is mandatory in workplaces, HMOs, blocks of flats, and almost any non-residential building in the UK. Domestic single-family homes don't need it, but commercial premises do. Typical installation cost runs £600–£3,500 for a small commercial unit, depending on size and the number of fittings required.

The system is regulated by BS 5266-1 and the Building Regulations Approved Document B. It's notifiable work under Part P (in dwellings) and is part of the Fire Safety Order's risk-assessment scope for commercial buildings.

What emergency lighting actually does

Emergency lighting comes in two functional categories:

• Escape route lighting — illuminates corridors, stairs and final exits so occupants can get out safely. Required everywhere on the escape path.
• Open area (anti-panic) lighting — provides general illumination in larger rooms (over 60 m²) to prevent disorientation and falls during evacuation.

Both must operate for at least 1 hour (3 hours in higher-risk premises like HMOs and care homes) on battery backup once mains fails.

Typical UK costs

Maintained vs non-maintained

• Non-maintained — only comes on when mains fails. Most common type, used on escape routes that aren't normally lit.
• Maintained — on all the time, switches to battery if mains fails. Used for "EXIT" signs and continuously lit areas.

Standalone vs central battery systems

Two ways to power emergency fittings:

• Self-contained fittings — each fitting has its own battery. Easier to install, simpler wiring, but each battery needs replacing every 4–5 years. Most common for small to medium sites.
• Central battery system (CBS) — one large battery cabinet powers all fittings via separate cabling. More expensive to install, but easier to maintain (one battery, not 30) and longer battery life. Used in larger buildings.

Testing and maintenance

BS 5266-1 requires:

• Monthly — short flick test (under 30 seconds) to confirm each fitting illuminates.
• Annually — full 3-hour discharge test to confirm batteries hold the rated duration. Records kept in a logbook.
• Self-test fittings — many modern LED units self-test monthly and self-discharge annually, logging results to a central panel. Highly recommended for sites with more than 10 fittings.

Failure to maintain emergency lighting is one of the most common Fire Safety Order non-compliances flagged in HMO inspections.

Things people often miss

• Risk assessment determines the spec — number, type and positioning of fittings come from the building's fire risk assessment, not a generic spec sheet. A pre-install fire risk assessment is the right starting point.
• EXIT signs must point in the right direction — sounds obvious but mistakes happen on multi-corridor sites. Compliance signage requires specific arrow positioning per BS 5499.
• Battery age — even unused emergency lighting batteries degrade after 4–5 years. Don't wait until a discharge test fails — proactive replacement is much cheaper than replacing post-failure across multiple fittings.
• Logbook — without a properly maintained logbook, the system is treated as untested in fire-officer eyes. A simple notebook listing date, tester name, fittings tested, and pass/fail is enough.
• HMO / multi-let landlord obligations — landlords of HMOs and blocks of flats are legally responsible for emergency lighting in common parts. Many don't realise this until a fire-officer inspection or a tenant complaint highlights the gap.

Frequently asked questions

Want a local pro to handle this? An electrician with emergency lighting and BS 5266 experience is the right call — many general electricians don't carry the right certification for system handover. Ask to see a recent example installation and the certification provided to the client.