Smoke & Fire Detection


  • Fire alarm installation
  • Fire alarm commissioning
  • Fire alarm maintenance

AC Gold Electrical Services Ltd provide a full smoke alarm and fire detection installation service to keep your property or portfolio of rental stock housing in compliance with all necessary legislation.

We install fire both commercial fire alarm systems (multiple detectors, sounders and call points) which meet Scottish building regulations and BS 5839: Pt.1:2013 and domestic fire alarm systems for new build, rental and house in multiple occupation (HMO) properties (interlinked, mains-powered, battery back-up) which need to conform with Scottish building regulations, BS 5839: Pt.6 and the Private Rented Housing Panel.

We can advise customers on the correct fire alarm, smoke alarm, or carbon monoxide detection system required to meet their legislative and legal obligations. A survey carried out at your property will enable us to provide an accurate quotation meets all regulatory requirements relating to fire, smoke and carbon monoxide regulations.

Scottish Building Standards Fire Alarm Requirements

The Scottish Government has updated the Scottish Building Standards 2015 to produce revised statutory guidance on the requirements for fire and smoke alarms, bringing it in line with British Standard 5839-6.

Guidance in the revised Scottish Building Standards Domestic Technical Handbook states there should be at least:

  • One functioning smoke alarm in the one room which is frequently used by the occupants for general daytime living purposes
  • One functioning smoke alarm in every circulation space such as hallways and landings
  • One heat alarm in every kitchen
  • All alarms should be Grade D, mains-powered with battery backup and interlinked (radio-link or hard-wired)
  • The number / position of the alarms depends on the size / layout of the house. There should be at least one alarm on each floor
  • All alarms should be installed in accordance with BS 5839 Part 6:2013 recommendations and the landlord must ensure the alarms are regularly maintained in accordance with the manufacturer’s recommendations

The landlord should install smoke and fire detectors that meet the Scottish building regulations and BS 5839 Part 6:2013 or be able to justify why a lesser level of protection is appropriate in a particular house.

If there is a requirement for a particular house to meet more stringent standards, then these more stringent standards apply.

The fitting of a hard wired smoke alarm may require a building warrant and the relevant local authorities should be consulted.

Fire Alarm Systems Grades & Categories

A fire alarm system which meets both Scottish Building Regulations and BS 5839-6:2013 requirements consists of 2 parts: the grade of the system and the category of the system.

Grade of system:

Fire alarm systems are grouped into 6 grades which covers the type of fire alarm system to be installed (battery, mains only, mains with back-up etc) and range in cost, complexity, reliability and level of monitoring.

Read more about Fire Alarm System Grades

Grade Description
A A full fire detection system with control and indicating equipment (eg, panel) installed to BS 5839-1. Similar to a commercial fire system with detectors, sounders and probably manual call points – all connected to a central control panel. Smoke and heat alarms cannot be used in a Grade A fire alarm system.
B Like grade A with some small amendments. Using simpler equipment.
C Fire detection system comprising separate detectors and sounders, or smoke/heat alarms, with central control equipment (eg, small indicating panel) mains powered with a back-up supply. Grade C is not widely used due to the difficulty in achieving some of the requirements.
D Fire detection system consisting of mains powered smoke and heat alarms with a back-up power supply.

Grade D is the most common grade to be found in dwellings and is the minimum requirement of BS 5839-6 and Scottish Building Regulations for most property types.

The back-up supply can be a primary battery (replaceable PP3 type), a secondary battery (sealed rechargeable type) or a capacitor. The PP3 back-up rechargeable type being mainly used in local authority and housing association properties due to the reduced maintenance requirements and having no battery to replace at regular intervals.

E Fire detection system consisting of mains powered smoke/heat alarms without back-up power supply.

This Grade is not recommended in most properties under BS 5839-6, so this effectively means Grade E is obsolete. Most manufacturers have now stopped production of Grade E alarms.

F Fire detection system consisting of battery only powered smoke/heat alarms.

This Grade is not acceptable under Building Regulations, or in rented properties, either new-build or existing, under the changes made in the 2013 revision of BS 5839-6. But it is acceptable in existing owner-occupied single-storey and 2 storey properties.

Category of system:

The extent of the system (the number of alarms installed and where).

Systems for life protection in dwellings are classified into 3 categories (LD1, LD2, LD3). The category tells the installer how many alarms are to be installed and where they should be fitted.

Learn more about Fire Alarm System Categories

Category Description
LD3 A fire alarm system installed in all circulation spaces that form part of the escape routes from the dwelling.

The most common installation would be one alarm in the hallway, and in multi-storey houses, an alarm on the landing of each additional floor level.

LD2 A fire alarm system installed in all circulation spaces that form part of the escape routes from the dwelling and in all rooms and areas that present a high fire risk to occupants.

This category is the same as the previous LD1 standard with the addition of extra alarms in high risk rooms.

Information contained within the BS 5839-6 standard indicates that the kitchen and the main living room (principle habitable room) are where additional alarms should be installed to meet the requirements of a category LD2 system.

LD1 A fire alarm system installed in all circulation spaces that form part of escape routes and all rooms or areas of the property where a fire may start – except for bathrooms, shower rooms and toilets.

This category covers the whole property with an alarm in all the rooms, but there could be justification for alarms in other areas, such as airing cupboards and roof spaces.

Fitting the right type of alarm

There are different types of smoke and heat alarms available which respond differently to various types of smoke or levels of heat, so are better suited to different areas of a property.

British Standard

All fire and smoke alarms should be 3rd party tested to a recognised British or European standard.

Smoke alarms (optical and ionisation) should be Kitemarked to BS EN 14604:2005.

Heat alarms should be Kitemarked to BS 5446-2:2003.

The Construction Products Regulations (CPR) came into effect on 1st July 2013 and demands that smoke alarms conforming to BS EN 14604 carry the CE mark and a unique identification number to demonstrate that they meet the requirements of the CPR.

Heat alarms are not covered under this regulation.

The diagram below will help to see what type of alarm to fit in the different areas of your property:

Multi-Sensor Fire Alarm

The Multi-Sensor contain both and optical and a heat sensor. It responds to both slow smouldering fires (Sofas, TVs) and fast flaming fires (Papers, Clothing)

Optical Smoke Alarm

Optical smoke alarms are particularly suitable for detecting smouldering fires (couches, TV’s) and the dense smoke given off by foam-filled furniture or burning PVC wiring, making them ideal for a lounge. They’re also less prone to nuisance alarms from kitchen fumes.

Heat Alarm

A Heat Sensor responds to a build-up in heat (triggerng at 58°C) from large flaming fires. It is well suited to a kitchen because it is less prone to being set-off by particles during cooking.

Ionisation Smoke Alarm

Ionisation smoke alarms are particularly good at responding to fast, flaming fires (paper, clothing) where there is little visible smoke. However, they are vulnerable to being set off by things such as cooking vapours and so can be a nuisance.


Don’t forget to test your smoke alarms!

Smoke alarms save lives, so it’s important to test them regularly, ideally once a week. Luckily it only takes seconds to do. Here’s some step by step instructions to show you how to test your smoke alarms:

Use these instructions to guide you through the process of testing the smoke and heat alarms in your property.

Testing smoke/heat alarm using the test button


Step 1:

Check that the power light (usually green) on the smoke/heat alarm is on and it is receiving mains power.

If it is off, check your fuseboard/consumer unit for a circuit marked which may be turned off. This may be labelled “smoke alarm/fire alarm” or may be installed on the same electrical circuit as the lights so that it is not turned off.

If it is off, turn it back on and check that the power light on the alarm is now on.


Step 2:

Press and hold the test button on the front of the alarm for around 10 seconds.

The alarm that you are testing should emit a loud audible alarm. Any other smoke alarms, heat alarms or carbon monoxide alarms fitted within your property should be interlinked and will therefore also be triggered to sound an alarm.


Step 3:

After tested one alarm successfully and having confirmed that the other interlinked alarms throughout the property also activated, you should repeat the process for the remaining alarms in your property. You should test each alarm even though you have already confirmed that they have been activated through the interlink system.

Testing smoke/heat alarm using a control switch


Step 1:

Check that the power light (usually green) on the smoke/heat alarm is on and it is receiving mains power.

If it is off, check your fuseboard/consumer unit for a circuit marked which may be turned off. This may be labelled “smoke alarm/fire alarm” or may be installed on the same electrical circuit as the lights so that it is not turned off.

If it is off, turn it back on and check that the power light on the alarm is now on.


Step 2:

Flick the control switch marked ‘Test Alarms’ to the “on” position.


Step 3:

The alarm that you are testing should emit a loud audible alarm. Any other smoke alarms, heat alarms or carbon monoxide alarms fitted within your property should be interlinked and will therefore also be triggered to sound an alarm


Step 4:

Flick the ‘Test Alarms’ switch on the control switch off.

The alarms should stop sounding.


Relevant Legislation for Fire, Smoke & Carbon Monoxide Alarms

This section contains any relevant legal legislation, building regulations etc which relate to fire, smoke and carbon monoxide alarm installations in rental properties in Scotland.

BS 5839: Pt.1:2013: Fire detection and fire alarm systems for buildings

Code of practice for design, installation, commissioning and maintenance of systems in non-domestic premises.

BS 5839: Pt.1:2013 provides recommendations for the planning, design, installation, commissioning and maintenance of fire detection and fire alarm systems in and around non-domestic buildings. It does not recommend whether or not a fire detection and fire alarm system should be installed in any given premises.

The term fire detection and fire alarm systems, in the context of BS 5839: Pt.1:2013, includes systems that range from those comprising just one or two manual call points and sounders – to complex networked systems that incorporate a large number of automatic fire detectors, manual call points and sounders, connected to numerous inter-communicating control and indicating panels.

The term also includes systems capable of providing signals to initiate the operation of other fire protection systems and equipment, such as fire extinguishing systems, smoke control systems or automatic door release equipment. Or safety measures such as the shutdown of air handling systems, closing of oil or gas valves or the grounding of lifts.

Contents for BS 5839: Pt.1:2013 includes:

Section 1: General Scope, Normative references, Terms and definitions, Need for a fire detection and fire alarm system and type of system, Categories of system, Exchange of information and definition of responsibilities, Variations from the recommendations of this standard.

Section 2: Design considerations, Relationship between system Category and areas protected, Actuation of other fire protection systems or safety facilities, Systems in explosive gas or dust atmospheres, System components, Monitoring, integrity and reliability of circuits external to control equipment, Detection zones, Alarm zones, Communication with the fire and rescue service, Audible alarm signals, Visual alarm signals, Fire alarm warnings for people with impaired hearing, Staged fire alarms, Manual call points, Types of fire detector and their selection, Spacing and siting of automatic fire detectors, Control and indicating equipment, Networked systems, Power supplies, Cables, wiring and other interconnections, Radio-linked systems, Electromagnetic compatibility, Electrical safety.

Section 3: Limitation of false alarms, Responsibility for limitation of false alarms, Categories of false alarms, Acceptable rate of false alarms, Causes of false alarms, Design process for limitation of false alarms, Measures to limit false alarms.

Section 4: Installation, Responsibility of installer, Installation practices and workmanship, Inspection and testing of wiring.

Section 5: Commissioning and handover, Commissioning, Documentation, Certification, Acceptance, Verification.

Section 6: Maintenance, Routine testing, Inspection and servicing, Non-routine attention.

Section 7: User’s responsibilities, Premises management, Logbook.

BS 5839: Pt.1:2013 supersedes BS 5839: Pt1:2002+A2:2008 which is now withdrawn.

BS 5839: Pt.6:2013: Fire detection and fire alarm systems for buildings

Code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in domestic premises.

BS 5839: Pt.6 is not written for householders, but provides guidance and recommendations for building professionals, enforcing authorities, contractors and others responsible for implementing fire precautions in buildings.

BS 5839: Pt.6:2013 covers fire alarm systems starting from a simple self-contained battery smoke alarm right through to major systems with central panel(s) in accordance to BS 5839: Pt1.

BS 5839: Pt.6 Code of Practice provides recommendations on fire safety in the home and was introduced in 1995 and affects landlords in the private or public sector whom are required to abide by these recommendations.

An update to the BS 5839: Pt.6 standard came out in 2013 and included common areas in sheltered housing. Carbon monoxide detectors were also permitted as fire alarm sensors and the requirement for rented accommodations were tightened.

While BS 5839: Pt.6 is primarily concerned with saving lives and reducing injuries, it does contain recommendations for helping to reduce property damage too. Good fire safety practice and adherence to the Code can give early warning of fire and help reduce the financial impact as well as human suffering.

Building Types

BS 5839: Pt.6 covers the following domestic building types: bungalows, multi-storey houses, individual flats, individual maisonettes, mobile homes, individual sheltered accommodation (and their common parts), houses in multiple occupation (HMOs), some NHS housing in the community, mansions, shared houses and houses divided into several self-contained single-family dwelling units.

The Grade System

BS 5839: Pt.6 grades fire detection systems from Grade F up to Grade A. Generally, the greater the fire risk, the more comprehensive the system needs to be.

The majority of fire detection systems installed by AC Gold Electrical Services are between Grade E and Grade D.

Grade F
System of one or more battery powered smoke alarms (+ heat alarms if required).
Grade E
System of interlinked mains powered smoke alarms (+ heat alarms if required) with NO stand-by supply. The interlink can be hard wired or radio-interlinked.
Grade D
System incorporating one or more interlinked mains powered smoke alarms (and heat alarms if required), each with an integral stand-by supply. The interlink can be hardwired or radio-interlinked.
Grade C
System consisting of fire detectors and alarm sounders (which may be smoke alarms) connected to a common power supply, comprising normal mains and stand-by supply, with central control equipment.
Grade B
Fire detection and alarm system comprising fire detectors (other than smoke alarms), fire alarm sounders and control and indicating equipment to either BS EN 54-2 (and power supply to BS EN 54-4), or to Annex C of BS 5839: Pt.6.
Grade A
Fire detection system incorporating control and indicating equipment to BS EN 54-2, and power supply to BS EN 54-4, installed to BS 5839: Pt.1 with some very minor exceptions.

The overwhelming number of residential applications in the UK will fall into the D to F categories.

Learn more about the grading system use for fire alarms.

Battery Powered Smoke Alarms – Grade F

BS 5839: Pt.6 acknowledges the advantages of the single, battery powered smoke alarm. They are simple to install and offer protection at very low cost. Battery powered smoke alarms conforming to BS EN 14604:2005 are recommended. Battery powered smoke alarms are typically suitable for owner-occupied buildings (existing buildings) with up to two storeys. Please note: if your property has multiple levels, it is recommended to have interlinked alarms. This is to ensure you receive the earliest possible warning of fire.

Single story tenanted properties were allowed in the last version (2004) of this standard to be fitted with Grade F alarms. This has now been changed to a grade D requirement. As an aside, landlords have now been found liable in cases where tenants themselves have disabled an alarm. For this reason, it is unlikely that landlords will be able to trust tenants to adequately look after a smoke alarm. The Code highlights the fact that battery powered smoke alarms are also only suitable for owner-occupied properties if the likelihood is, that batteries will be replaced within five days of a low battery signal.

Mains Powered Smoke Alarms without Back-up Battery – Grade E

The Code (BS 5839: Pt.6) does not recommend an application for alarms without back-up power source any longer. Grade E systems have serious drawbacks: power cuts or the termination of supply for whatever reason disables them totally. They can be rendered useless by the tripping of a protective device, or even by the fire itself. Householders may also disable them at the mains all too easily if false alarms are a problem. AC Gold Electrical Services Ltd do not recommend the installation of grade E smoke alarms without backup battery.

Mains Powered Smoke Alarms with Back-up Battery – Grade D

The problems outlined above can be overcome by using mains powered alarms that incorporate, within each alarm, a stand-by supply such as a primary or rechargeable battery. The alarms have to be interconnected either through wiring or radio-interlink. The mains power supply can come from a dedicated power supply directly from the fuse box or from the nearest permanently powered light fitting, as long as the smoke alarm heads can be removed without removing the base as well.

Grade D is required for new, owner-occupied buildings of up to three storeys, two storey rented properties and existing, owner-occupied buildings of more than two storeys. Very large storeys (>200m2) might require Grade B alarm system.

A question remains for landlords – can they be sure that their tenants are paying their electricity bills? Given that many tenants may have low incomes (in many local authorities, 70% or more of all tenants are on subsidised incomes), they may well experience periods of disconnection – and yet the landlord could well be liable if the alarm fails to sound because the tenant has not paid his or her bills! Unfair or not, as the law stands, it obviously makes good commercial sense to ensure that a reliable, ideally re-chargeable and sealed-in backup battery is in place.

The minimum back-up duration recommended is 72 hours, and the Code acknowledges that there could well be circumstances where a longer stand-by period is justified e.g. tenants’ inability to pay their electricity bill.

Fire Detectors supplied with Power from a common Power Supply Unit – Grade A, B, C

More expensive high specification systems can offer connection of all fire detection devices to a common power supply via low voltage transformers, or interlinked fire and security systems. Again, a minimum 72 hour back-up is recommended by the Code. Due to the complexity of A, B and C Grades, we have omitted the descriptions from this short guide.

BS 5446-2:2003

The BS 5446-2:2003 (published 21st March 2003) specifies requirements and type test methods for heat alarms. It applies specifically to heat alarms intended solely for permanent installation on ceilings or walls of dwellings and heat alarms suitable for use in leisure accommodation vehicles (LAVs).

Building Regulations Technical Handbook No.2

The Building Regulations Technical Handbook No.2 covert fire safety in all dwellings, houses, bungalows and flats. The document is not in itself legislation, but The Building (Scotland) Act 2003 give Scottish Ministers the power to make Building Regulations, and the Technical handbook is an approved means of meeting these requirements. It applies to any new-build property and existing buildings where a material alteration to the property has taken place, such as an extension or loft conversion.

The Scottish Government’s Building Regulations Technical Handbook No.2 covers a wide range of fire safety requirements; means of escape, communication of fire, internal fire spread, external fire spread and access for the fire service. The information in this manual is restricted to ‘communication of fire’ e.g a fire alarm system.

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