Battery-only smoke alarms haven't been compliant for new installations or rentals for years. Current standards (UK Building Regs Part B, Scottish Tolerable Standard) require mains-wired alarms with battery backup, and crucially interlinked — when one goes off, they all do.
Standard install for a 3-bed house: smoke alarm in each storey's circulation space (hallway, landing), heat alarm in the kitchen, optionally CO alarm near the boiler. All interlinked, all hardwired, all registered with the manufacturer.
£120 covers a typical 3-alarm install when there's existing alarm wiring (most modern homes). Properties needing fresh cabling cost more — typically £200-350 depending on layout.
How it works
Common questions
Why do they need to be interlinked?
Because a smoke alarm in your kitchen won't wake you upstairs at 3am. Interlinking means a fire detected anywhere triggers every alarm in the house simultaneously. This is now the legal standard in Scotland and best practice everywhere.
RF or hardwired interlink?
Both work. Hardwired is the older standard and bulletproof. RF (radio-frequency) interlinking is faster to install in retrofits and equally reliable. We use whichever suits the property.
What about battery alarms?
Standalone battery alarms are not compliant for rental properties or new builds. For owner-occupiers in older homes they're better than nothing — but a hardwired interlinked system is a one-time £150 investment that protects you for 10 years. Worth it.
How often do they need replacing?
Sensor cells degrade. Every 10 years is standard — set a calendar reminder for the install date + 10 years. Your installation date is printed on each alarm.
Do you do CO (carbon monoxide) alarms too?
Yes, and we recommend them in any home with a gas appliance, oil burner, or solid fuel (wood/coal). They sit in the same standard. CO alarms often have a 10-year life like smoke alarms now.
Scotland specifically?
Yes — Scottish Tolerable Standard (Tolerable Standard) requires smoke alarms in all living rooms and circulation spaces, heat alarm in the kitchen, all interlinked, all mains-wired. Came into force February 2022. We're fully aware of the requirements.