gl-15 fire safety engineered alternative building solutions[1]

8/3/2019 GL-15 Fire Safety Engineered Alternative Building Solutions[1]

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THIS IS A CONTROLLED DOCUMENT

COMMUNITY DEVELOPMENT RESEARCH AND LIAISON

T:\BUILT ENVIRONMENT BRANCH\GUIDELINES\GL15


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The standard of the brief or report has been deemed suitable by FESA; and

FESA is in agreement with the contents and methodology used; and

The relevant BCA Performance Requirement(s) have been addressed to the satisfaction

of FESA; and

The Alternative Solution is compatible with Fire Brigade requirements.

3.3 FESA strongly recommends that performance-based Alternative Solutions should not beapplied to fire safety aspects of facilities or buildings used for bulk storage or processing

of flammable liquid, industrial chemicals or explosive materials.

Note: compliance with other regulatory requirements (outside of the BCA) may be required for

special use buildings.

3.4 FESA strongly advocates the use of sprinklers in the occupancies listed in Table E1.5 ofthe BCA. Fire sprinkler systems provide a high degree of protection to life and propertyand greatly assist the fire suppression activities and safety of FESA fire fighters.

3.5 A performance-based Alternative Solutions should account for and facilitate Fire Brigadeintervention where it is deemed relevant to do so by the BCA or FESA. In accounting for

Fire Brigade intervention, fire-fighters should be given a reasonable time to rescue any

remaining occupants, before conditions in the building or structure become untenable or

unsafe for fire fighters.

Note: the need to consider rescue activity should be determined in consultation

with FESA, within the context of the building occupancy characteristics.

3.6 A performance-based Alternative Solution should not use Fire Brigade intervention, in

isolation, as a means or justification to reduce the BCAs requirements for fire resistancelevels of a buildings structural elements.

3.7 FESA endorses both the Australian Building Codes Boards (ABCB) International Fire

Engineering Guidelines, current edition, and the Engineers Australias (Society of Fire

Safety) Code of Practice for Fire Safety Design, Certification and Peer Review.

4. PERFORMANCE REQUIREMENTS ASSESSED BY FESA:

FESA will generally only provide comment on its assessment of Alternative Solutionsaddressing the following Performance Requirements:

4.1 SECTION C FIRE RESISTANCE

CP1(i) A building must have elements which will, to the degree necessary, maintainstructural stability during a fire appropriate to - ... Fire Brigade intervention.

CP2(b) Avoidance of the spread of fire must be appropriate to - Fire Brigade

intervention.


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CP9 Access must be provided to and around a building, to the degree necessary,for Fire Brigade vehicles and personnel to facilitate Fire Brigade intervention

appropriate to -

4.2 SECTION D ACCESS AND EGRESS

DP5 To protect evacuating occupants from a fire in the building exits must be fire-isolated to the degree necessary, appropriate to - Fire Brigade

intervention.

4.3 SECTION E SERVICES AND EQUIPMENT

EP1.3 A fire hydrant system must be provided to the degree necessary to facilitatethe needs of the Fire Brigade appropriate to -

EP1.4 An automatic fire suppression system must be provided to the degreenecessary to control the development and spread of fire appropriate to - ......

EP1.5 Suitable means of fire fighting must be installed to the degree necessary in abuilding under construction to allow initial attack by construction workers

and for the Fire Brigade to undertake attack on the fire appropriate to

EP1.6 Suitable facilities must be provided to the degree necessary in a building to

co-ordinate Fire Brigade intervention during an emergency appropriate to -

EP2.1 In a building providing sleeping accommodation, occupants must be providedwith automatic warning on the detection of smoke so they may evacuate in

the event of a fire to a safe place.

EP2.2(b) In the event of a fire in a building the conditions in any evacuation route mustbe maintained for the period of time occupants take to evacuate the part of the

building. The period of time occupants take to evacuate referred to in (a)must be appropriate to - Fire Brigade intervention

EP3.2 One or more passenger lifts fitted as emergency lifts to serve each floorserved by the lifts in the building, must be installed to facilitate the activitiesof the Fire Brigade and other emergency services personnel.

EP4.3 To warn occupants of an emergency and assist evacuation of a building, anemergency warning and intercommunication system must be provided, to the

degree necessary appropriate to -

However, comment on aspects of alternative solutions that address other elements of the BCAmay be provided to Approval Authorities in accordance with the legislatory requirements as

considered appropriate in the circumstances.

5. FESA CONSULTATION:

5.1 Initial consultation with FESA regarding the use of an alternative solution for building

works that deviate from the Deemed-to-Satisfy (DtS) provisions of the BCA should occur

by way of:


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Written correspondence, minuted meetings or specific FEB deliberation meetings, where

all stakeholders:

o Discuss the BCA (DtS) non-complianceso Discuss the Performance Requirements to be addressed

o Agree the methodology to be used for meeting the Performance Requirements,

including design fires and fire safety strategies

o Discuss (as appropriate) the qualifications and experience of the consultantfire safety engineer undertaking the fire safety engineering analysis.

o Determine whether a formal FEB is required, or whether FESA will supportthe preparation of the FSER without a formal FEB being agreed.

o Address other issues that may be of concern to FESA.

5.2 Following initial consultation and prior to the commencement of the FSER, it is

recommended that the fire safety engineer or Alternative Solution proponent gain in-principle support from FESA to proceed with the report for the proposed Alternative

Solution.

5.3 Following initial consultation and on receipt of in-principle support from the FESA for

the proposed Alternative Solution, a FSER in accordance with Section 7 of this guideline

should be furnished to FESA for comment.

Note: FESA requires a hard (paper) copy of all preliminary documentation and an electronic

copy of the final FSER.

6. FIRE SAFETY ENGINEERING DESIGN BRIEF (FEB):

6.1 It is recommended that in order to minimise or avoid delays in gaining FESA

endorsement of the alternative solution, initial consultation in accordance with Section 5

of this guideline should be followed.

6.2 In the interests of an efficient building design approval process, an FEB meeting should

be attended by the relevant stakeholders in the building project. Such stakeholders may

include all or some of the following as applicable:

FESA personnel

Local Government, Building Surveyor or other approving authority

Fire safety engineer(s)

Fire services consultants

Architect or designer

Building regulations consultant

Building owner(s)/management

Occupant/client representative

Hydraulic / Structural / Electrical / Mechanical - engineer(s)

Project management representative.


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6.3 FEB meeting minutes should be provided to all participants by the convener of the

meeting for verification and include the following information:

Date and venue of meeting and all attendees.

Scope of project.

Project (building) description including:

o Building location Street name and number and Lot No

o Type of building construction

o Rise in storeys

o Floor area and volume

o Occupancy classification and occupant characteristics

o Specific hazards

The Performance Requirements to be addressed (FESA will only provide an

assessment of the Performance Requirements listed in Section 4) BCA DtS non-compliances

Proposed active and passive fire safety features

Proposed methodology(s) for achieving compliance with BCA Performance

Requirements (BCA Clause A0.5)

Proposed assessment method(s) (BCA Clause A0.9)

Proposed fire safety engineering Evaluation Extent(s) used.

Fire safety engineering Sub-systems to be considered

Assumptions used.

Proposed fire safety engineering tools to be employed for analysis and relevant

validation information on them.

Proposed design fires and fire scenarios.

Acceptance criteria for the fire safety engineering analysis for each Alternative

Solution.

Proposed treatment of uncertainty where required, i.e. sensitivity analysis.

Proposed or required management-in-use regimes.

7. FIRE SAFETY ENGINEERING REPORT (FSER):

7.1 The final document containing the fire safety engineering analysis and methodology to

demonstrate that the alternative solution has addressed the relevant BCA PerformanceRequirements, should be entitled Fire Safety Engineering Report.

Note: FESA requires the FINAL FSER documentation to be submitted in electronic

format (pdf).

7.2 The FSER should be written clearly and concisely and in a manner that persons externalto the fire safety engineering profession could understand and follow. Fire safety

engineering terminology should be explained and acronyms should be written out in full

when they first appear in the report.


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7.3 Any data, findings, research, statistics or evidence of suitability detailed in the report

should be clearly referenced in order to demonstrate their authenticity (where applicable,

a copy of data or references used in support of a proposal should be included as addenda

to the report).

7.4 The FSER is to include the following:

Scope of the project

Report reference details

Project (building) description (as outlined under Point 6.3)

Details of the relevant Performance requirements

Details of the BCA DTS non-compliances

An explanation of why the design of the building cannot meet the DTS provisions.

Proposed active and passive fire safety features, i.e. Trial Concept Design and generalspecifications (e.g. OH1 sprinkler system using RTI 40 fast response sprinkler heads)

Proposed methodology(s) for achieving compliance with BCA performance

requirements (BCA Clause A0.5)

Proposed assessment method(s) (BCA Clause A0.9)

Fire safety engineering Sub Systems analysed

Assumptions used.

Analysis input data used and/or expert judgment discussions

Proposed fire safety engineering tools to be employed for analysis and relevantvalidation information on them (where applicable)

Agreed design fires and fire scenarios (where applicable) Agreed acceptance criteria for the fire safety engineering analysis for each Alternative

Solution

Treatment of uncertainty, ie sensitivity analysis (where required)

Results of the analysis clearly presented

Proposed or required Management-in-Use regimes

Clear, unambiguous conclusions and recommendations made by the author

A copy of the building plans used to compile the report (these may be included in

electronic form).

A copy (in electronic format) of the input files necessary to allow any fire modellingto be run for review purposes should be provided for assessment purposes.

7.5 The FSER should detail all of the fire safety related essential services in the building

project and include recommendations for an essential services maintenance regime to be

followed by the building owner after the building construction and commissioning phase.

7.6 The Fire Engineer must make available to all the stakeholders as well as those responsible

for installing, commissioning and maintaining the buildings passive and active fire

safety features, systems and essential services, any FESA conditions required for the

acceptance of the FSER.


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7.7 When using expert judgment, the relevant accreditation details, qualifications and

industry related experience of the party providing the judgement, should be detailed in the

FSER.

7.8 The FSER should be consistent with the methodologies detailed in the IFEG.

7.9 The author or the person verifying the fire safety engineering report is to certify in

writing that the alternative solution/s has/have addressed the relevant Performance

Requirement(s).

7.10 An FSER is not to be undertaken by a person who has been utilised for building

surveying or certification purposes on the project.

7.11 For some alternative solutions there is a reliance on a specific usage of a particular

building Classification (eg a low fire loading associated with Class 8 stone masonry orsimilar) or on particular equipment being used (eg a gantry crane restricting the usablecompartment volumes). Where a change of these circumstances would negate the

applicability of the alternative solution without requiring further referral to the Approval

Authority, (ie there is no change of use) then an appropriate, enforceable mechanism for

addressing the necessary variation to the fire safety system requirements in the case of a

change of conditions should be agreed and included in the FSER

8.0 BASIC FIRE ENGINEERING CRITERIA

In the absence of other suitably referenced and justified inputs, the following standard

values or input criteria will be considered to be suitably conservative and acceptable foruse in calculations and modelling for engineering analysis.

8.1 RTI

For calculation of sprinkler or other alarm activation times the following RTIs are

considered appropriate for use with the associated activation temperatures.

Detector Type Value

Standard response sprinkler heads RTI = 150

Fast response sprinkler heads RTI = 50

Thermal detectors RTI = 10Smoke detectors RTI = 1 (using a temperature rise of 5

0C in

accordance with Bukowski & Averill, 1998)

8.2 Sprinkler Activation

Where the HRR of a fire is to be calculated in order to provide a peak fire size and the

fire location is sprinkler protected, then the activation time based on the location of the

second row of sprinkler heads (as per diagram below) should be used to add suitable

robustness to the analysis.


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For the prevention of ignition, maximum heat flux values of less than 12.6kW/m2 should

be achieved. Note this is for piloted and non-piloted ignition in accordance with BSI

Published Document PD7974 Part 3.

8.4 Tenability Criteria for Building Occupants

A clear air layer height of 2.1m (ie above head height). However, if occupants are

expected to be subjected to a smoke layer then the visibility through, and toxicity of, the

smoke are to be analysed. In these circumstances it would be expected that the inputs to

the fire modelling for the design fire chosen will produce smoke characteristics that

closely replicate the likely combustion products of the building contents.

A maximum hot layer temperature of 2000C (to ensure that radiant heat to the occupants

below is less than 2.5kW/m2).

Where the building occupants are subjected to convected heat it would be considered

appropriate for the maximum temperature to be not in excess of 600C where the water

vapour content of the air is likely to be high (ie as in most fire scenarios).

8.5 Tenability Criteria for Fire Fighters

Routine Conditions

Elevated temperatures, but not direct thermal radiation

o Maximum Time: 25 minutes

o Maximum Air Temperature: 100

o

C (at 1.5m)o Maximum Radiation: 1kW/m

2

Hazardous ConditionsWhere fire fighters would be expected to operate for a short period of time in high

temperatures in combination with direct thermal radiation.

o Maximum Time: 10 minutes

o Maximum Air Temperature: 120oC (at 1.5m)

o Maximum Radiation: 3kW/m2

Extreme Conditions

These conditions would be encountered in a snatch rescue situation or a retreat from a

flashover.

o Maximum Time: 1 minute

o Maximum Air Temperature: 160o

C (at 1.5m)

o Maximum Air Temperature: 280o

C (in upper layer)

o Maximum Radiation: 4-4.5kW/m2


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8.6 Occupant Characteristics

Movement speeds

Level travel Fully mobile 0.93 m/s

Mobility difficulty 0.80 m/s

Stair movement upwards Fully mobile 0.50 m/sMobility difficulty 0.24 m/s

Stair movement downwards Fully mobile 0.50 m/s

Mobility difficulty 0.17 m/s

(All values based on SFPE Handbook 3rd

Edition data)

8.7 Occupant Flow

Effective width of exit = Exit width - (2 x boundary layers)

Boundary layer widths as follows:

Element Boundary Layer Width (each side)

Stairway 150 mm

Handrails 90 mm

Corridor, Ramp walls 200 mm

Obstacles 100 mm

Door 150 mm

Flow rate = 1.0 person/s/m of effective width for average occupancy. For high densityoccupant loading refer to the SFPE Handbook or other appropriate reference document.

8.8 Soot Yield

When an input for soot yields for fire modelling is required it would be considered

appropriate to use the following values as per the published values for various materials.

(1) For general use, a soot yield value of 0.1g/g (approximated from that of polyester.

(2) Where it is known that the use of high soot yield values will be appropriate eg

where significant quantities of polystyrene or polyurethane materials may beinvolved, then a soot yield value of at least 0.22g/g would be considered

appropriate.

8.9 Fire Modelling

Where the modelled design fire is based on a sprinkler controlled scenario it is considered

that zone models (such as BRANZFIRE and CFAST) are not sufficiently technically

robust to assess the likely effects of sprinkler activation and cooling where CFAST will

only consider a homogeneous hot layer above a cooler lower layer. The use of a

computational fluid dynamics modelling package, such as Fire Dynamics Simulator

(FDS), to assess conditions for occupants would be considered appropriate.


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8.10 Other Criteria

If this list of criteria does not include sufficient suitable information to resolve any query

relating to appropriate values/ scenarios/ acceptance criteria for the purposes of an FEBor FSER, additional information may be obtained by contacting the FESA Built

Environment Branch on (08) 9323 9855.

9.0 HYDRANT TESTING

Some Alternative Solutions rely on the results of street main hydrant testing in support of

the viability of the Alternative Solution. For consideration of the viability of proposed

alternative solutions it is advised that the hydrant testing results provided should be

recent (within 6 months of the date of submission) and supported by appropriatecertification to indicate that at the time of test the testing equipment used was certified as

calibrated in accordance with the requirements of a NATA accredited laboratory.

However, it is noted that the final acceptance of a system will depend on the results of

FESA testing carried out when the building is completed.

10. POST CONSTRUCTION AND COMMISSIONING OF BUILDING.

10.1 It is recommended that prior to FESA carrying out any post construction testing or

inspection, that the fire safety engineer should be involved during the commissioning

phase for the fire safety system installations. This will ensure that the building design, asconstructed, is consistent with assumptions made in the FSER and the input data used in

the analysis.

This will also assist in ensuring that the fire safety systems have been installed asspecified in the trial concept design of the FSER. The fire safety engineer should ensure

that the fire safety systems operate and interface with each other as required in a timely

and reliable manner to the requirements of the BCA and relevant Australian Standards

and in accordance with the requirements of the FSER.

10.2 Prior to FESAs involvement in post construction testing, the fire safety engineer shouldprovide the FESA with written confirmation that:

Any approved conditions of FESA Alternative Solutions endorsement have been met;

and The construction of the building is consistent with the design detailed in the FSER; and

The fire safety systems and features stipulated in the FSER have been installed and

commissioned satisfactorily; and

The FSER has been delivered and understood by the building owner or manager, prior tooccupancy of the building; and

All management in use and maintenance regimes are in place, have been acknowledged

by the building owner or management and will be complied with by the building owner

or building manager; and


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All of the essential services considered by the trial design should be included in a

schedule incorporated into the Management in Use policies for the building. Copies of

the schedule should be provided to the building owner and FESA; and

The essential services in the schedule are to be maintained in accordance with SectionI1.1 of the BCA and the schedules and recommendations of the system(s) designer and/or

installer(s) and the relevant Australian Standard, for the life of the building.

Where specific details, such as staffing levels or occupant training are included, they

must be included in the Management in Use policies for the building and strictly

applied.

10.3 As far as practicable, the fire safety engineer should also be present when FESA iscarrying out the post construction testing and inspection of fire safety systems so that any

problems and deficiencies identified by FESA may be discussed and resolved in a timely

manner.

REFERENCES:

Australian Building Codes Board (ABCB) National Construction Code Series (current

edition)

ABCB NCC Guide to Volume One (current edition)

ABCB International Fire Engineering Guidelines (IFEG) 2005

LEGISLATION:

Local Government (Miscellaneous Provisions) Act 1960.

Building Regulations 1989.

Please note: FESA Guidelines are available on the FESA Website: www.fesa.wa.gov.au at:

http://www.fesa.wa.gov.au/regulationandcompliance/buildingplanassessment/pages/publications.aspx .

gl-15 fire safety engineered alternative building solutions[1]

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