Fire Safety

Your Guide For Smoke Alarm Positioning To Meet Building Regulations

What are the Building Regulations?

Building Regulations are the minimum standards set for the design, construction and alterations to buildings. They are regularly changed and updated by Government, and are approved by Parliament. Fundamentally, the Building Regulations work to ensure the health and safety of those using the building, and help conserve on fuel and power. They cover all aspects of construction, including foundations, damp-proofing, the overall stability of the building, insulation, ventilation, heating, fire protection and means of escape in case of fire. They also ensure that adequate facilities for people with disabilities are provided in certain types of building.

Fire Safety

Fire safety is one of the key sections within the Building Regulations, which outlines the requirements needed to provide an early warning of fire, escape routes, preventing the spread of fire, and providing access to fire fighting facilities for the Fire and Rescue Services.

BS 5839

Fire Building Regulations in the UK point towards

 BS 5839 as they key code of practice for the planning, design, installation, commissioning and maintenance of fire detection. (BS 5836-6 for domestic, and BS5839-1 for non domestic)

BS 5839-6:2013 categorises different grades and categories of fire detection systems for different types of building. Generally, the greater the fire risk and the more demanding the application required, the more comprehensive the fire safety system needs to be.

Here is a quick overview for specifying a fire detection and fire alarm system:

    1. There are 6 Grades of system, from A to F, with A being the most comprehensive fire detection system. (e.g. what the system comprises)
    1. Fire detection systems are divided into different Categories that relate to the level of protection the system provides (e.g. where the detectors are fitted)

*Please refer to this when positioning  fire alarms to meet Building Regulations

Smoke alarm positioning to meet Building Regulations

Building Regulations vary throughout the UK, and so specify different levels of fire safety when installing fire alarm systems. Please refer to:

All Building Regulations recommend:

  1. Fire detection systems should be provided in accordance with the relevant recommendations of BS 5839-6.
  2. All alarms should be interlinked to ensure audibility throughout property
  3. (As outlined in BS 5839-6) smoke alarms positioned in circulation areas should be of optical type (or multi-sensor type incorporating an optical sensor).

As fire safety technology continues to advance, multi-sensor alarms (those monitoring for more than one indication of fire e.g. smoke and heat) are becoming increasingly available and affordable. These provide a quicker, more reliable, response to fire – so giving occupants more time to escape – and also reduce the risks of false alarms. Find out more in the blog What Is FireAngel Multi-Sensor Technology?


LD3 – Minimum protection

In England, the minimum guide for smoke alarm positioning to meet building regulations is as follows:

  • All dwellings should be provided with an alarm system to at least Grade D, Category LD3
  • Position optical or multi-sensor mains powered alarms with an integral backup power supply within the escape routes of the property (i.e. hallways and landings)
  • Have at least one smoke alarm on every storey
  • Install a heat alarm in any kitchen areas where the kitchen is not separated from the circulation space or stairway by a door.
  • All alarms must be interlinked

IMPORTANT to note:

  • Category LD3 only offers a minimum level of protection in circulation spaces
  • Best practice to install to Category LD2. This is as BS 5839-6 states that “a Category LD3 system cannot be expected, with any degree of reliability, to protect people who might be involved with the fire at ignition or in its early stages.”
  • LD2 is required in Scotland and Northern Ireland Building Regulations (see below) and it is expected that England and Wales will follow suit when Building Regs are next revised.


LD2 – Medium protection

In Scotland and Northern Ireland, the guide for smoke alarm positioning to meet building regulations is as follows:

  • Install smoke alarms in all circulation areas/ escape routes and high risk areas
  • Have at least one smoke alarm in every circulation space on each storey (such as hallways and landings)
  • Position at least one smoke alarm in the principal habitable room (generally the living room)
  • Have at least one heat alarm installed in every kitchen.
  • All alarms must be interlinked

In Scotland the Regulations also require:

  • At least one smoke alarm in every access room serving an inner room


In Scotland optical or multi-sensor alarms are recommended for the principle habitable room and all circulation areas. Heat alarms are recommended for the kitchen.

In Northern Ireland the Regulations recommend optical alarms for the principle habitable room and all circulation areas. Heat alarms are recommended for the kitchen. FireAngel’s Multi-Sensor smoke alarms combine the very latest in optical sensing with thermal enhancement for a faster response and would therefore be suitable for installation in the principle habitable room and all circulation areas.

LD1 – High protection

If the risk to occupants from fire in any part of the premises is deemed to be high, a Category LD1 system would be appropriate.

For example, an LD1 system would be appropriate if the occupants live with a form any disability (mental or physical) that could delay their escape from fire. Other vulnerable individuals may also include the elderly or children – it is all relative to the length of time needed for a tenant to escape.

Installing alarms to meet LD1 in the Building Regulations would be as follows:

  • Smoke alarms installed in all circulations spaces that form part of escape routes, and in all areas where a fire may start (excluding bathrooms)
  • Areas where a fire may start include hallways, landings, living room, kitchen and bedrooms.

For more information on BS 5839-6 & Building Regulations please see:

  1. Our clear and comprehensive guide by Ian Ballinger – Certification Manager for FireAngel

Alternatively, please see our guides on:

  1. Carbon Monoxide Regulations In The UK
  2. Fire Safety Standards And Regulations For Existing Social Housing
  3. Making Fire Safety Legislation Simple For Private Landlords UK