2021 Scottish Legislation
Announced in February 2019 and in effect from February 2021, the Scottish Government updated legislation covering fire alarms in domestic properties. The new requirements, "Tolerable Standard Guidance: Satisfactory Fire Detection and Satisfactory Carbon Monoxide Detection", apply to all homes in Scotland and cover smoke, heat, and carbon monoxide alarms, as appropriate. A general summary of the new requirements are:
- One smoke alarm in the room most frequently used during the daytime.
- One smoke alarm in every circulation space on each storey (e.g. hallways and landings).
- One heat alarm in each kitchen.
- The smoke and heat alarms must be ceiling-mounted and interlinked.
- Where there is a carbon-fuelled appliance (e.g. boiler or gas cooker) or a flue, a carbon monoxide alarm is also required.
- All types of alarm must be mains powered (fixed wiring, not a mains plug) OR powered by a tamper-proof lifetime battery.
- All alarms must be regularly maintained and tested in accordance with the manufacturer's instructions.
For smoke and heat alarms, it can be compared to (which can interlink) from BS 5839-6: 2019 – see our full guide to BS 5839 Part 6 for more details on types of alarm.
It is the property owner's responsibility to ensure these alarms are correctly installed and the guidance page on gov.scot outlines advice for various types of shared ownership and tenements.
Alarm Power Requirements
To comply with the updated Scottish legislation, smoke and heat alarms must be Grade D2, D1, or F1. Battery-powered Grade F1 models can only be used if they support interlinking, so care must be taken to select suitable products as most Grade F1 alarms on the market are stand-alone models. Please see the table below for more details on the Grades of alarm.
Carbon monoxide alarms do not use the same Grade distinction as smoke and heat alarms, so you must simply pay attention to the manufacturer's information regarding power source. The power requirements for carbon monoxide alarms are the same as for smoke and heat alarms: either a tamper-proof battery that lasts the full lifespan of the product, or wired into a mains circuit in the property.
Any mains-powered alarms, regardless of sensor type, must be permanently wired into a mains circuit. Alarms which use a mains plug are not suitable for the updated regulations.
Smoke & Heat Alarm Grades
British Standard 5839 Part 6 is a code of practice relating to the design, installation and maintenance of fire detection systems in domestic premises. The standard also grades fire detection systems which reflects their functionality and capability. The below table details the up-to-date grades for fire detection systems.
Alarm Grades by Power Type (BS 5839 Part 6)
|BS 5839-6: 2019 Grade
||Alarm Power Type
||Battery Operated (Lithium)
||System of one or more battery-powered smoke alarms (and heat alarms if required). The battery must be tamper-proof and last the full life of the alarm.
||Battery Operated (Alkaline)
||System of one or more battery-powered smoke alarms (and heat alarms if required). The battery is user-replaceable and will not last the full life of the alarm.
||Mains Powered (Lithium Back-up)
||System incorporating one or more interlinked mains-powered smoke alarms (and heat alarms if required), each with an integral stand-by supply. They can be hardwire-interlinked or radio-interlinked. The stand-by supply must be tamper-proof and last the full life of the alarm.
||Mains Powered (Alkaline Back-up)
||System incorporating one or more interlinked mains-powered smoke alarms (and heat alarms if required), each with an integral stand-by supply. They can be hardwire-interlinked or radio-interlinked. The stand-by supply is user-replaceable and will not last the full life of the alarm.
||Mains Powered (Dedicated Circuit + Back-up)
||System consisting of fire detectors and alarm sounders (which may be domestic smoke alarms) connected to a common power supply, comprising normal mains and stand-by supply, with central control equipment.
||Mains Powered (Panel - Built-in PSU + Back-up)
||Fire detection system incorporating control and indicating equipment to BS EN 54-2, power supply to BS EN 54-4, and installed to BS 5839 Part 1, with some very minor exceptions.
For a full summary of BS 5839 Part 6, please visit 'Fire Detection and Fire Alarm Systems for Buildings'.
Smoke alarms, heat alarms, and carbon monoxide alarms powered from a mains circuit will usually also have an interlink or interconnect terminal next to the live and neutral wire terminals. If one alarm detects a fire or CO emergency it will pass the signal to the other units which will also sound an alarm throughout the property. This is particularly important for large buildings or if the bedroom is located far away from the kitchen. Outhouses and garages can also be connected into the radio-interlinked alarm system for added peace of mind.
Mains alarms can be connected to nearby lighting circuits for power, provided the light switch does not also turn off power to the alarm, but the interlink wire must be separate and not 'piggy-back' on a mains circuit as smoke, heat, and CO alarms are not designed to take 230V in their interlink terminal. If the property does not already have mains-powered alarms wired in, or if testing one of your existing alarms does not also cause the other alarms to sound, then an electrician will need to install a new interlink cable throughout the building.
Radio-interlinked smoke alarms, heat alarms, and carbon monoxide alarms communicate with each other via radio frequency (RF). If one alarm detects a fire or CO emergency it will pass the signal to the other units which will also sound an alarm throughout the property. This is particularly important for large buildings or if the bedroom is located far away from the kitchen. Outhouses and garages can also be connected into the radio-interlinked alarm system for added peace of mind.
Radio-interlinked alarms are sometimes referred to as wireless alarms, although this can be confusing when dealing with radio-interlinked units wired into the mains power supply in a building. Radio-interlinked alarms can be battery powered or mains powered, and we even offer battery operated smoke alarms, heat alarms, and carbon monoxide alarms with radio-interlink that contain a sealed battery which lasts the full ten years of the alarm's life.
Only interlink alarms with alarms from the same model range and manufacturer. Alarms from different manufacturers are not compatible and attempting to interlink them could damage the alarms. If in doubt, check the instruction manual for the alarms before purchase – we provide PDF instruction manual downloads for the majority of smoke, heat, and CO alarms on our website.
Some ranges support mixing hardwired and radio-interlink alarms in the same network, which can reduce electrician costs and disruption. All alarms on each storey would be connected together via hardwire interlink, with one alarm on each storey also being connected to each other via RF signal. This could also save money on product costs, as mains-powered alarms without radio-interlink are usually the cheapest option for interlinking alarms. Please confirm before purchase if you require this functionality.