1

DFES Built Environment Branch Technical Note

Issue: October 2021 Authorised: Manager Direct Brigade Alarm & Superintendent Built Environment Branch

TN-10/21: ALARM DELAY, ALARM INVESTIGATION

FACILITIES AND FALSE ALARM MITIGATION

MEASURES - DFES ACCEPTANCE

1. INTRODUCTION This document provides guidance regarding false fire alarm mitigation measures for new or existing fire

detection and alarm systems installed in accordance with AS1670.1.

False fire alarm mitigation measures may be needed to reduce the risk of a buildings fire alarm system

activating due to non-fire related events, which may occur where occupants are carrying out normal day to

day activities within a building (cooking, steam from showering, spraying aerosols, and maintenance

works/cleaning which create dust).

It is important to identify and address the real causes of the false alarms before opting to make changes to

the fire alarm system. A detailed record of false fire alarm incidents should be maintained by the building to

assist in appropriately identifying the causes of false alarms, these records will inform the appropriate

solution.

If all other options have been investigated - such as determining ventilation is adequate, addressing

behaviours (such as the induction and management of trades onto site), ensuring the maintenance of the

fire alarm system is adequate, and where a building has had a change of occupancy, identifying and

mitigating the impact this may have had on the fire alarm system – and false fire alarms are still occurring,

this is when changes to the fire alarm system may be required.

When implementing a performance solution or a delay into a fire alarm system as a false alarm mitigation

measure, the type of solution must be carefully selected and programmed. The building type and occupants’

characteristics as well as any existing Performance Solutions must be considered to ensure changes do

not impact the fire alarm safety systems of the building, insurance coverage, firefighting operations, or the

safety of occupants.

2. ACCEPTANCE CRITERIA FOR CHANGES TO THE FIRE ALARM SYSTEM

The fire engineer (private consultant) must confirm a new performance solution or other mitigation measure

will not negatively impact any existing Performance Solutions, occupant evacuation and firefighting

operations.

3. ALARM DELAY MITIGATION METHODS SUMMARY

2

Below table 1 lists the alarm delay mitigation methods relating to building classification and where they are

acceptable under AS1670.1, AS4428.1 and DFES position. Please note delay facilities are to be a function

of the Fire Detection Control and Indicating Equipment (FDCIE) only. No independent delay facility is

permitted to the Occupancy Warning System (OWS) or Emergency Warning and intercom Systems

(EWIS).

Table 1 Alarm mitigation methods

- Alarm Acknowledgment

Facility (AAF)

- Alarm Delay

Facility (ADF)

- Alarm Verification

Facility (AVF)

- Alarm Investigation

Facility (AIF) Class 2 Yes Yes Yes No

Class 3 Yes Yes Yes Yes

Class 4 Yes Yes Yes Yes

Class 5 No No Yes Yes

Class 6 No No Yes Yes

Class 7a No No Yes Yes

Class 7b No No Yes Yes

Class 8 No No Yes Yes

Class 9a No No Yes No

Class 9b No No Yes

Yes (stadia and recreation

centres only)

Class 9c No No Yes No

Above criteria are based on the following:

• AAF – based on AS1670.1 only.

• ADF – based on AS1670.1 only.

• AVF – based on AS1670.1 only.

• AIF – based on AS 1670.1, AS4428.10 and DFES position. Notes: Refer to AS1670.1 for further details on AAF, ADF and AVF + Appendices (A, B & C

respectively)

Refer to AS 4828.10 and AS1670.1 for further details on AIF + Appendix D - Alarm Investigation Facility (AIF)

4. DFES EXPECTATIONS PER BUILDING CLASSIFICATION

Building Classification 2

BCA Definition:

Class 2: a building containing two or more sole-occupancy units.

Expectations:

DFES preferences for Class 2 apartment buildings experiencing multiple false alarms are:

a) Determine and address the real causes of false alarms before adopting a performance solution or

adding a delay (e.g. building design issues, occupant behaviours, lack of ventilation, inadequate

maintenance of the system).

b) If a performance solution is required, AS1670.1 smoke detection system is to be retained (i.e.

replacing smoke detectors with thermal only detectors is not acceptable).

3

a) Option 1: Consider an AVF Type A Dependency before any other delay. b) Option 2: If cooking facilities are provided, adequate exhaust / ventilation is to be provided c) Option 3: Consider ADF (in combination with thermal/multisensor or sprinkler) or AAF. Local

detection sounder base required for both ADF & AAF delays. d) Option 3: Remove AS1670 detection from SOU’s and replace AS 3786 240V smoke alarms.

The delay periods should not default to the maximum allowed in the standard. The delay type and period

should be confirmed / discussed with DFES.

The alarm system should achieve a minimum sound pressure level of 75dB(A) at all bed heads, with all doors

closed if installed to AS 1670.1 2015 or previous. AS 1670.1 2018 should achieve 75dB(A) throughout

occupied spaces of SOU’s.

Building Classification 3

BCA Definition:

Class 3: a residential building providing long-term or transient accommodation for a number of unrelated persons, including the following:

(1) A boarding house, guest house, hostel, lodging house or backpacker accommodation. (2) A residential part of a hotel or motel. (3) A residential part of a school. (4) Accommodation for the aged, children, or people with disability. (5) A residential part of a health-care building which accommodates members of staff. (6) A residential part of a detention centre. (7) A residential care building.

Expectations:

DFES preferences for Class 3 hotel & short-term accommodation buildings experiencing multiple false alarms

are:

a) Determine and address the real causes of false alarms before adopting a performance solution or adding a delay (e.g. building design issues, occupant behaviours, lack of ventilation, inadequate maintenance of the system).

b) If a performance solution is required, AS1670.1 smoke detection system is to be retained (i.e. replacing smoke detectors with thermal only detectors is not acceptable). o Option 1: Consider AVF Type A Dependency before any other delay. o Option 2: If cooking facilities are provided, an adequate exhaust / ventilation is to be provided o Option 3: Consider ADF (in combination with thermal/multisensor or sprinkler). Local detection

sounder base required for both ADF delays. o Option 4: Consider AIF Delay Facility if all other alternatives have been implemented or

considered unsuitable. Additional safety measures may be required for sleeping accommodation such as addition of thermal detection and local warning of occupants.

The delay periods should not default to the maximum allowed in the standard. The delay type and period

should be confirmed / discussed with DFES.

The alarm system should achieve a minimum sound pressure level of 75dB(A) at all bed heads, with all doors

closed if installed to AS 1670.1 2015 or previous. AS 1670.1 2018 should achieve 75dB(A) throughout

occupied spaces of SOU’s.

Building Classification 4

BCA Definition:

Class 4: a dwelling in a Class 5, 6, 7, 8 or 9 building.

Expectations:

DFES preferences for Class 4 accommodation within other classification type buildings experiencing multiple

false alarms are:

a) Determine and address the real causes of false alarms before adopting a performance solution or adding a delay (e.g. building design issues, occupant behaviours, lack of ventilation, inadequate maintenance of the system).

4

b) If a performance solution is required, AS1670.1 smoke detection system is to be retained (i.e. replacing smoke detectors with thermal only detectors is not acceptable). o Option 1: Consider AVF Type A Dependency before any other delay. o Option 2: If cooking facilities are provided, an adequate exhaust / ventilation is to be provided o Option 3: Consider ADF (in combination with thermal/multisensor or sprinkler). Local detection

sounder base required for both ADF delays. o Option 4: Consider AIF Delay Facility if all other alternatives have been implemented or

considered unsuitable. Additional safety measures may be required for sleeping accommodation such as addition of thermal detection and local warning of occupants.

The delay periods should not default to the maximum allowed in the standard. The delay type and period

should be confirmed / discussed with DFES.

The alarm system should achieve a minimum sound pressure level of 75dB(A) at all bed heads, with all doors

closed if installed to AS 1670.1 2015 or previous. AS 1670.1 2018 should achieve 75dB(A) throughout

occupied spaces of SOU’s.

Building Classification 5

BCA Definition:

Class 5: an office building used for professional or commercial purposes.

Expectations:

DFES preferences for buildings experiencing multiple false alarms are:

a) Determine and address the real causes of false alarms before adopting a performance solution or adding a delay (e.g. building design issues, occupant behaviours, lack of ventilation, inadequate maintenance of the system). o Option 1: Consider fire detection type suitable for areas of use. o Option 2: Consider AVF Type A Dependency. o Option 3: Consider AVF Type B Dependency in protected areas that are suitable. o Option 4: Consider AIF Delay Facility if all other alternatives have been implemented or

considered unsuitable.

The delay periods should not default to the maximum allowed in the standard. The delay type and period

should be confirmed / discussed with DFES.

Building Classification 6

BCA Definition:

Class 6: a shop or other building used for the sale of goods by retail or the supply of services direct to the public, including—

(1) an eating room, café, restaurant, milk or soft-drink bar; or (2) a dining room, bar area that is not an assembly building, shop or kiosk part of a hotel or motel; or (3) a hairdresser’s or barber’s shop, public laundry, or undertaker’s establishment; or (4) a market or sale room, showroom, or service station.

Expectations:

DFES preferences for buildings experiencing multiple spurious alarms are:

a) Determine and address the real causes of false alarms before adopting a performance solution or adding a delay (e.g. building design issues, occupant behaviours, lack of ventilation, inadequate maintenance of the system).

b) Option 1: Consider fire detection type suitable for areas of use. c) Option 2: Consider AVF Type A Dependency. d) Option 3: Consider AVF Type B Dependency in protected areas that are suitable. e) Option 4: Consider AIF Delay Facility if all other alternatives have been implemented or considered

unsuitable. The delay periods should not default to the maximum allowed in the standard. The delay type and period

should be confirmed / discussed with DFES.

5

Building Classification 7a, 7b, 8

BCA Definition:

Class 7a: a carpark - Class 7b: a building that is used for storage, or display of goods or produce for sale by wholesale - Class 8: a process type building , a laboratory, a building in which production, assembling, altering, repairing, packing, finishing, or cleaning of goods or produce for sale takes place.

Expectations:

DFES preferences for buildings experiencing multiple spurious alarms are:

a) Determine and address the real causes of false alarms before adopting a performance solution or adding a delay (e.g. building design issues, occupant behaviours, lack of ventilation, inadequate maintenance of the system). o Option 1: Consider fire detection type suitable for areas of use. o Option 2: Consider AVF Type A Dependency. o Option 3: Consider AVF Type B Dependency in protected areas that are suitable. o Option 4: Consider AIF Delay Facility if all other alternatives have been implemented or

considered unsuitable. The delay periods should not default to the maximum allowed in the standard. The delay type and period

should be confirmed / discussed with DFES.

Building Classification 9b

BCA Definition:

Class 9b: an assembly building including a trade workshop or laboratory in a primary or secondary

school.

Expectations:

DFES preferences for buildings experiencing multiple spurious alarms are:

a) Determine and address the real causes of false alarms before adopting a performance solution or adding a delay (e.g. building design issues, managing occupant behaviours, lack of appropriate ventilation systems, lack of maintenance of the system). o Option 1: Consider fire detection type suitable for areas of use. o Option 2: Consider AVF Type A Dependency. o Option 3: Consider AVF Type B Dependency in protected areas that are suitable. o Option 4: Consider AIF Delay Facility if all other alternatives have been implemented or

considered unsuitable.

The delay periods should not default to the maximum allowed in the standard. The delay type and period

should be confirmed / discussed with DFES.

Building Classification 9a & 9c

BCA Definition:

Class 9a: a health care building - Class 9c: a residential care building.

Expectations:

DFES preference is:

a) It is not recommended to add any delays to the detection system. o Option 1: Consider fire detection type suitable for areas of use. o Option 2: Consider AVF Type A Dependency.

6

Mixed-use building

Buildings with multi-classification are reviewed on a case-by-case basis. Depending on the location of false

alarms and where it is proposed to add a delay (e.g. throughout or in one portion of the building), above

expectations may differ.

5. Direct Brigade Alarm (DBA)

Changes to any Direct Brigade Alarm fire detection systems require consultation and approval by DFES

DBA. When an existing Performance Solution already exists, approval of both DFES DBA and DFES fire

engineering sections is required. The application must be lodged online. Please refer to Appendix E for

further details on the process.

Changes or modifications to the operation of these life safety systems may also trigger the requirement for

a building permit from the Local Government. Once all required approvals are obtained for the changes to

the fire alarm system, the fire alarm contractor doing the works must complete and submit DFES C8 form,

the C8 must be approved before any works are carried out to the fire alarm system.

7

Consultation process within DFES

The following chart highlights DFES internal process.

DBA FALSE ALARM

S

Regulation and Compliance Branch

(RCB)

Building owner/s

Built Environment Branch Fire Engineering Team

(BEB DBA)

Built Environment Branch Direct Brigade Alarm

Team (BEB DBA)

RCB will contact building owner/s. RCB will provide guidance on process and DFES expectations (Guidance Note: False Fire Alarm Mitigation Measures).

❖ Application for AIF Submission to be lodged to BEB DBA. Until a separate AIF lodgement form in place, lodgement is to be via FEB lodgement form process.

Submission to be as per Appendix D -

Alarm Investigation Facility (AIF)

Application for AAF/ADF/AVF Submit ‘C8 Form’ to Fire Alarm Monitoring Service (FAMS) Note: BEB FE may review submissions relating to the installation of ADF, should there be existing Alternative/Performance Solutions.

BEB FE will provide advice directly to building owner/s. A copy of the advice letter will be sent to BEB DBA and RCB.

OR

Regulation and Compliance Branch

(RCB) Building owner/s

(DFES Contractor) Fire Alarm Monitoring

Services

FAMS will directly contact BEB DBA

Prior to any submissions - Building owners and/or their representatives should meet with DFES BEB FE and/or DBA to discuss proposal/design options.

8

References:

• Building Code of Australia

• Australian Standard AS 1670.1 Fire detection, warning, control and intercom system – system

design, installation and commissioning. Part 1: Fire

• Australian Standard AS 1670.2 Fire detection, warning, control and intercom system – system

design, installation and commissioning. Part 2: Local Fire

• Australian Standard AS 4428.10 Fire detection, warning, control and intercom system – control and

indicating equipment

Legislation:

• Building Act 2011

• Building Regulations 2012 (as amended)

Contractual Agreement:

• DFES DBA End User Agreement

9

Appendix A - Alarm Acknowledgment Facility (AAF)

AAF is a localised (e.g. sole occupancy unit (SOU) or individual apartment) manual push button facility that

will delay the building-wide alarm function of smoke detection for a period of time. When the fire alarm

activates within a SOU and an AAF is installed, the occupant must push the button (within 30 - 60s of the

local alarm sounding) which will delay building wide alarm and DBA activation while the occupant

investigates the cause of the alarm and/or clears the detector of any non-fire related contaminants (e.g.

steam, aerosol, smoke from cooking). If the detector is cleared within the required time-frame (0-180

seconds), the fire alarm system will return to normal and will not escalate to building wide alarm and DBA

activation.

AAF requires occupants to be aware and competent in its operation and will not be suitable for all types of

buildings i.e. short stay accommodation. It requires management/induction procedures and occupant

familiarity to be effective.

Basic features:

✓ AAF operate independently of any other AAF.

✓ Each AAF controls only one SOU.

✓ The FDCIE should operate up to two AAF. If more than two AAF are activated, then the alarm should

be initiated without any delay.

✓ Each ADF shall incorporate at least one local Audible Alarm Device (producing at least 75dB(A) @1m.

✓ Upon smoke detection activation, the acknowledgement period can up to 60s (30s increments

maximum).

✓ The investigation period is up to an additional 180s (60s increments maximum).

✓ If smoke has not been cleared during the investigation period, then a fire alarm condition shall be generated by the FDCIE.

10

11

Appendix B - Alarm Delay Facility (ADF)

ADF is a FDCIE feature where the smoke detector within a SOU on initial detection of smoke or similar

particles is programmed to automatically delay the building wide alarm and DBA activation for a fixed

period (0-300 seconds). Following the delay period, the detector will reset/resample the air and if particles

remain, it will trigger building wide alarm and DBA activation.

ADF is used when false alarms are expected due to non-fire events, where occupants are carrying out

normal activities such as spraying aerosols, having showers causing steam, smoking, vaping, dust from

cleaning/trade activities and smoke or steam from cooking activities. These activities can all set off a smoke

detector and cause building wide alarm and DBA activation

Where ADF is provided, if the detector is cleared of the contaminates within the required time-frame, the fire

alarm system will return to normal and will not escalate to building wide alarm and DBA activation. In the

event of a real fire event, the thermal detection or sprinkler will activate or if contaminate (smoke) will not be

cleared during delay period the fire alarm system will escalate to building wide alarm and DBA activation.

It should be noted the existing fire panel needs to be able to support ADF. Older panels that do not support

ADF will need to be upgraded.

Basic features:

✓ Each ADF controls only one SOU.

✓ ADF shall include a separate heat detection component of the fire safety strategy, i.e. heat detectors

or sprinklers.

✓ Each ADF shall incorporate at least one local Audible Alarm Device (producing at least 75dB(A) @1m.

✓ The FDCIE should only operate up to five ADF.

✓ Thermal detection should automatically initiate the building-wide fire alarm function.

✓ Upon smoke detection activation, a delay period up to 300s (60s increment maximum) starts. If

smoke, or other particles, have not been cleared during this period, then a building-wide fire alarm

condition shall be generated by the FDCIE.

12

13

Appendix C - Alarm Verification Facility (AVF)

AVF is a feature to delay building wide alarm and DBA activation via two versions Type A Dependency and

Type B Dependency.

Type A Dependency will detect smoke or similar particles and resamples within 0- 60 seconds to confirm

whether particles are still present.

Type B Dependency will detect smoke or similar particles and wait for a second confirmatory detector

activation to confirm whether particles are still present.

AVF is used when false alarms are expected due to natural or forced dispersal of particles caused by non-

fire events such as aerosols and small amounts of steam or dust.

AVF is generally used to mitigate brief changes in the environment, which happen from time to time in a

building, such as a wind gust carrying dust or other contaminates which can set off a smoke detector. Instead

of going straight to full building wide alarm and DBA activation.

DFES approval is not required for AVF Type A Dependency, Type B Dependency should be discussed and

approved by DFES.

Basic features:

✓ Type A Dependency – it shall be possible to receive a confirmation alarm signal at least from the

same fire detector within 60 seconds of receipt of the first alarm signal

✓ The first alarm state shall be automatically cancelled within 30 minutes of receipt of the first alarm

signal.

✓ Type B Dependency – following the receipt of a first alarm signal, the entry to the fire alarm condition

may be inhibited until the receipt of a confirmation alarm signal from another fire detector

An audible indication via fire alarm condition or fault warning condition on the FDCIE.

14

15

Appendix D - Alarm Investigation Facility (AIF)

The Australian Standard AS 4428.10 defines AIF as being part of the control and indicating equipment that

delays the transmission of a fire alarm to provide time for manual acknowledgment and investigation. Only

the fire brigade can approve the installation of AIF.

Building owners, managers or agents who experience frequent false fire alarms may consider incorporating

an AIF in their fire detection and alarm system; however, before AIF is considered, all below criteria must

be met:

✓ An AIF should not be considered as the primary means of overcoming false alarm activations. The

cause of the alarms be investigated and mitigated before pursuing this option, AIF will generally only

be considered after all other options have been explored and implemented by a premise, details of

the mitigation actions taken and investigation findings will be required to be submitted to support any

application for AIF.

If engaged to undertake review / modifications, all aspects causing false alarms must be investigated

and addressed accordingly:

➢ Management processes are reviewed and amended where required (e.g. signage,

procedures, policies, induction of trades etc).

➢ Systems maintenance is reviewed and confirmed as adequate.

➢ Ventilation provisions are reviewed for adequacy (e.g. natural or forced ventilation,

system capacity, location, etc).

➢ Detection systems are reviewed for adequacy (e.g. detector type, detector location,

existing delay facilities, etc).

➢ The building design is appropriate for occupancy type.

✓ AIF will not be approved where a building is experiencing false alarms caused by system related

issues (detector malfunctions, sprinkler pressure fluctuations etc).

✓ AIF may only be installed where the installation has been reviewed and endorsed by DFES.

✓ DFES will not support the installation of AIF in:

➢ health care buildings where the occupants are mainly non-ambulatory; and

➢ buildings accommodating the aged, children or occupants with disabilities.

✓ AIF settings:

➢ The acknowledgement time can be up to 30s.

➢ The investigation time can be up to 300s.

➢ The investigation time period is to be agreed with DFES.

➢ The AIF is to be incorporated only in detection systems where staff trained in its operation

are present.

- AIF will only be activated, when in attended mode.

- If AVF is also installed: It must be disabled when AIF is in the attended mode,

i.e. both delays cannot be active.

✓ Other fire safety systems should complement AIF to limit potential negative effects resulting from a

delay in activating the occupant warning system or notifying the fire. Examples of systems are as

follows:

➢ Sprinkler systems.

➢ Sound system and Intercom System for Emergency Purposes (SSISEP) (previously

16

known as Emergency Warning and Intercommunication Systems (EWIS))

✓ The presence of combustible cladding (façade) should be considered when reviewing the submission.

✓ Where an immediate response is critical for firefighters to undertake life safety emergency operations,

the installation of AIF should not be pursued.

17

Appendix E – Application for Alarm Investigation Facilities

This section provides guidance to building owners, managers, and agents on DFES requirements when

applying to DFES for acceptance of the installation of an AIF into new and existing fire detection and alarm

systems.

When making application to DFES for the installation of an AIF, it is necessary to provide a comprehensive

report, to the DFES Built Environment Branch, documenting the following aspects:

✓ State the known causes of false fire alarm;

✓ Provide information on what action/s has/have been taken to reduce the number of false alarms;

✓ Detail any existing fire safety facilities that would complement the installation of an AIF;

✓ Provide staff procedures that will be implemented to manage the installation and operation of the AIF

devices, e.g. Who, What, Where, When etc.;

✓ Provide a training program for the implementation and reoccurring operation of the proposed AIF

devices;

✓ Provide a declaration (dated and signed by the owner/s) that the AIF will be installed and operated in

strict compliance with Australian Standards 4428.10 – 1998 Fire detection, warning, control and

intercom systems - Control and indicating equipment, Part 10: Alarm investigation.

✓ The fire engineer (private consultant) should detail all existing alternative/performance solutions and

confirm that the installation of AIF will not impact the existing fire safety strategy.

18